1 Let a = 5.2 and b = 4.7.
a Find the exact value of 3a + b3.
Xena estimates that the answer to part a is 140.
b Find the percentage error made by Xena in her estimation.

Answers

Answer 1

Part (a)

Replace every 'a' with 5.2 and replace every 'b' with 4.7

Then use your calculator to evaluate.

3a + b^3 = 3*5.2 + (4.7)^3 = 119.423

Answer: 119.423

===============================================

Part (b)

The true value is 119.423 which is the result of part (a)

The estimated value is 140

Subtract the two values

140-119.423 = 20.577

and divide that over the true value

20.577/140 = 0.14697857142858

Which, when rounded to 4 decimal places, we get 0.1470

Move the decimal place over to the right 2 spots to get 14.70%

Answer: 14.70% error (approximate)

Related Questions

Prove that “The sum of the angles in a triangle is 180“.

Answers

Answer

See below :)

Step-by-step explanation:

Experimental Verification

Step 1 : Three triangles with different shapes and sizes are drawn. Suppose the name of each triangle is ABC.

( Draw the triangles in such a way that you can each angle by using a protractor )

( See attached picture )

Step 2 : Measure each angle of these three triangles with the help of protractor and fill up the following table.

_________________________________

Figure < A < B < C < A + <B + <C Result

-------------------------------------------------------------

( i ) 180°

--------------------------------------------------------------

( ii ) 180°

-------------------------------------------------------------

(iii) 180°

________________________________

Conclusion : The sum of the angles of any triangle is equal to 180°

Theoretical proof

( See attached picture )

Given : <ABC , <BCA and <BAC are the angles of ∆ABC.

To prove : <ABC + <BCA + <BAC = 180°

Construction : Through the vertex A , a straight line XY parallel to BC is drawn.

Proof :

_________________________________

Statements Reasons

------------------------------------------------------------

1. < XAB = <ABC 1. XY // BC and alternate

angles

------------------------------------------------------------

2. <YAC = <BCA 2. XY//BC and alternate

angles

------------------------------------------------------------

3. <XAB + <BAC + 3. whole part axiom

<YAC = <XAY

----------------------------------------------------------

4. <XAB + <BAC + 4. < XAY is a straight angle.

<YAC = 180°

-------------------------------------------------------------

5. <ABC + <BAC + 5. from statements ( 1 ),

<BCA = 180° ( 2 ) and (4)

_______________________________

Proved

Hope I helped!

Best regards!!

Is (0,3), (0,7), (4,0) a function

Answers

Answer:

no because it has 2 of the same x-intercepts.

Step-by-step explanation:

The midpoint of JK is M(8,9). One endpoint is J(10, 10). Find the coordinates of the other
endpoint K.
Write the coordinates as decimals or integers.
K= (1,7)

Answers

Answer:

[tex]K(6,8)[/tex]

Step-by-step explanation:

Given

Midpoint, M = (8,9)

J = (10,10)

Required

Find K

The midpoint of segments is calculated using;

[tex]M(x,y) = (\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2})[/tex]

Where [tex]x = 8[/tex] and  [tex]y = 9[/tex]

Take J as J(x1,y1);

So:

[tex]x_1 = 10[/tex]     [tex]y_1 = 10[/tex]

Substitute values for x and y in the given formula

[tex](8,9) = (\frac{10 + x_2}{2}, \frac{10 + y_2}{2})[/tex]

Solving for x2, we have

[tex]8 = \frac{10 + x_2}{2}[/tex]

Multiply both sides by 2

[tex]2 * 8 = \frac{10 + x_2}{2} * 2[/tex]

[tex]2 * 8 = 10 + x_2[/tex]

[tex]16 = 10 + x_2[/tex]

Make x2 the subject of formula

[tex]x_2 = 16 - 10[/tex]

[tex]x_2 = 6[/tex]

Solving for y2

[tex]9 = \frac{10 + y_2}{2}[/tex]

Multiply both sides by 2

[tex]2 * 9 = \frac{10 + y_2}{2} * 2[/tex]

[tex]2 * 9 = 10 + y_2[/tex]

[tex]18 = 10 + y_2[/tex]

Make y2 the subject of formula

[tex]y_2 = 18 - 10[/tex]

[tex]y_2 = 8[/tex]

So,

[tex](x_2,y_2) = (6,8)[/tex]

So, the coordinates of K is

[tex]K(6,8)[/tex]

Sandy loves to ride her skateboard on her ramp. Sandy wonders how she could make her skateboard go faster. She thinks that the height of her ramp may play a role in the top speed reached by her skateboard. How should sandy set up her experiment to test her hypothesis? What would the independent variable be? What is the dependent variable?

Answers

Answer:

Null hypothesis : top speed = height

Alternative hypothesis : top speed ≠ height

Dependent variable : speed

Independent variable : Height

Step-by-step explanation: The experiment aims to determine the relationship between the height of ramp and the top speed reached by her skateboard.

The Null hypothesis: top speed = height

while the alternative hypothesis will negate the Null.

Alternative hypothesis : top speed ≠ height

The dependent variable in the experiment will be her top speed, because it is the variable we want to evaluate. We want to determine if thwre will be a change in the top speed of the skateboard if there is change in another variable 'height' of ramp. The variable which might cause a change in value of our dependent variable is called the independent or predictor variable, which in this case is the height variable.

-6 times (-6) times (-6)

Answers

Answer:

-216

Step-by-step explanation:

-6 x -6 =36

36 x -6 = -216

Answer:

-216

Step-by-step explanation:


1. There are 10 students in the class and 40 eggs. If
the eggs are divided equally among the students how
many does each student get?

Answers

Answer:

4 eggs

Step-by-step explanation:

40 divided by 10 = 4

Answer:

4

Step-by-step explanation:

40/10=4

Please explain how you get the answer.
Convert decimals to fractions
10) 0.34
11) 0.252525....
12) 5.7777....

Answers

Answer:

0.34 ends in the hundredths place. so the fraction will be over one hundred

34/100 -- simplify this by dividing each side by 2: 17/50

0.252525... is a repeating decimal

set up an equation so the numbers to the right of the decimal place are the same

100x = 25.2525...

x = 0.2525...

subtract

99x = 25

divide

x = 25/99

5.7777... is also a repeating decimal

set up an equation so the numbers to the right of the decimal place are the same

10x = 57.777...

x = 5.777...

subtract

9x = 52

x = 52/9

2
A circle has the equation x^2+ y^2 + 6x - 8y + 21 = 0.
a) Find the coordinates of the centre and the radius of the circle.

The point P lies on the circle.
b) Find the greatest distance of P from the origin.

Answers

Answer:

a) (-3, 4) and radius = 2.

b) 7 cms.

Step-by-step explanation:

x^2+ y^2 + 6x - 8y + 21 = 0

x^2 + 6x + y^2 - 8y = -21

Completing the square on the x and y terms:

(x + 3)^2 - 9 + (y - 4)^2 - 16 = -21

(x + 3)^2 + (y - 4)^2  = -21 + 9 + 16 = 4

a) So the center is (-3, 4) and the radius = sqrt4 = 2.

Ill come back to you later with the second part.

(b) For the point P to be a maximum distance from the origin the line must pass through the center of the circle:

Distance of the center from origin:

= √(-3 - 0)^2 + (4 -0)^2)

= 5.

So the dsitance of P from  the origin is  5 + radius

= 7 cm.

4 + 6x + 5 = 7x Could someone help me? Thanks :) And could you also show how u did it

Answers

Answer:

x=9

Step-by-step explanation:

combine like terms

[tex]4+6x+5=7x[/tex]

4+5=9

9+6x=7x

to get 6x with 7x subtract 6x from both sides as its positive

6x-6x=0

7x-6x=x

9=x

x=9

r - 7 = 1
can someone help me with this

Answers

Answer:

[tex]r=8[/tex]

Step-by-step explanation:

[tex]r-7=1[/tex] add seven to both sides

[tex]r=1+7\\r=8[/tex]

Hope this helps

Answer:

The correct answer to this problem is r = 8.

Step-by-step explanation:

To solve this problem, we have to remember that our goal is to get the variable (in this case, r) by itself on one side of the equation.  To do this, we have to get rid of the -7 on the left side of the equation.  Therefore, our first step is to add 7 to both sides of the equation.  This gives us:

r - 7 = 1

r - 7 + 7 = 1 + 7

r = 8

Thus, your answer is r = 8.

Hope this helps!

Help ASAP!! I’m confused on only this question!

Answers

Answer:

Second choice

Step-by-step explanation:

f(x) = (1/4)(x + 4)^2 - 9

f(x) = (1/4)(x^2 + 8x + 16) - 9

f(x) = (1/4)x^2 + 2x + 4 - 9

f(x) = (1/4)x^2 + 2x - 5

(1/4)x^2 + 2x - 5 =

= (1/2 x + 5)(1/2 x - 1)

Answer: Second choice

Un globo vuela entre dos ciudades A y B, que distan entre sí 1.500 m. Los tripulantes del globo ven la ciudad A con un ángulo de depresión de 27°, mientras que para ver la ciudad B es de 36°.

Answers

Answer:

La altura del globo con respecto al suelo es 449,6 metros.

Step-by-step explanation:

La afirmación está incompleta. El enunciado completo es: "Un globo vuela entre dos ciudades A y B, que distan entre sí 1.500 m. Los tripulantes del globo ven la ciudad A con un ángulo de depresión de 27°, mientras que para ver la ciudad B es de 36°. ¿Cuál es la altura aproximada del globo con respecto al suelo?

El diagrama geométrico de la situación se encuentra descrita en el archivo adjunto. La altura aproximada del globo puede obtenerse con ayuda de las funciones trigonométricas, en este caso, se recomienda utilizar la función tangente de los ángulos de depresión:

Ciudad A

[tex]\tan 27^{\circ} = \frac{h}{1500\,m-x}[/tex]

[tex]0,510 = \frac{h}{1500\,m-x}[/tex]

Ciudad B

[tex]\tan 36^{\circ} = \frac{h}{x}[/tex]

[tex]0,727 = \frac{h}{x}[/tex]

Donde [tex]h[/tex] y [tex]x[/tex] son la altura con respecto al suelo y la distancia horizontal con respecto a la ciudad A.

A continuación, se elimina la altura de ambas ecuaciones por igualación y se determina la distancia horizontal del globo con respecto a la ciudad A:

[tex]0,727\cdot x = 0,510\cdot (1500\,m-x)[/tex]

[tex]1,237\cdot x = 765\,m[/tex]

[tex]x = 618,432\,m[/tex]

Finalmente, la altura del globo con respecto al suelo es:

[tex]h = 0,727\cdot x[/tex]

[tex]h = 0,727\cdot (618,432\,m)[/tex]

[tex]h = 449,600\,m[/tex]

La altura del globo con respecto al suelo es 449,6 metros.

What is (0,6) after a reflection over the y-axis?

Answers

Answer:

Still (0,6)

Step-by-step explanation:

The point is actually on the y-axis.  It can't change in a y-axis reflection, only in an x-axis reflection.

Joshua is preheating his oven before using it to bake. The initial temperature of the
oven is 75º and the temperature will increase at a rate of 25° per minute after being
turned on. What is the temperature of the oven 7 minutes after being turned on?
What is the temperature of the oven t minutes after being turned on?
Temp after 7 minutes:
Temp after t minutes:

Answers

Answer:

1) [tex]\huge\boxed{ 250\°}[/tex]

2) [tex]\huge\boxed{75\° + 25\°t }[/tex]

Step-by-step explanation:

Initial Temperature = 75°

Per minute Increase = 25°

After 7 minutes:

=> 75 + 25 ( 7 )

=> 75 + 175

=> 250°

After t minutes:

=> 75 + 25 (t)

=> 75° + 25°t

Answer:

[tex]\Large \boxed{\mathrm{a) \ 250\° \ \ \ b) \ 75\° +25\°t}}[/tex]

Step-by-step explanation:

Before baking, Joshua preheats the oven at an initial temperature of 75°. The temperature increases at a rate of 25° per minute.

Temperatute after 7 minutes,

[tex]75 \° + 25 \°(7)=75\° +175 \° =250 \°[/tex]

Tempertaure after t minutes,

[tex]75 \° +25 \° t[/tex]

Naya sells half the paintings in her collection and gives one-third of her paintings to friends, while she keeps the remaining paintings for herself. What fraction of her original collections does she keep?

Answers

Answer:

[tex]R = \frac{1}{6}[/tex]

Step-by-step explanation:

Given that she sold half the paintings and gives out one-third

Required

Determine the fraction left with her

The relationship between the paintings is as follows;

Sold Paintings + Giveaway Paintings + Remaining Paintings = 1

From the question;

Sold Paintings = 1/2

Giveaway = 1/3

Represent Remaining Paintings with R

Substitute these values in the above formula

[tex]\frac{1}{3} + \frac{1}{2} + R = 1[/tex]

Take LCM

[tex]\frac{2+3}{6} + R = 1[/tex]

[tex]\frac{5}{6} + R = 1[/tex]

Make R the subject of formula

[tex]R = 1 - \frac{5}{6}[/tex]

Take LCM

[tex]R = \frac{6-5}{6}[/tex]

[tex]R = \frac{1}{6}[/tex]

Hence, the fraction of the paintings left with her is [tex]\frac{1}{6}[/tex]

Noah has one dollar composed of dimes and nickles. He has twice as many 1 point
dimes as nickels, How many nickles does he have? *
Your answer

Answers

no❤️   ,,,,,,,,,,,,,,,,,,,      

8 dimes 4 nickels

ur crazy bb why’d you even ask this question

Fully simplify.
-11xy2(13x2y3)

Answers

Answer:

-11xy\26x\2y\6

Step-by-step explanation:

A certain number is increased by 30 and the result is divided by two. The number obtained is three times the original number. Find the number.
Plss show working​

Answers

Answer:

x = 6, PLEASE MARK AS BRAINLIEST

Step-by-step explanation:

Let this number be x:

1) Increase x by 30 = x + 30

2) Divide the result by 2 = [tex]\frac{x+30}{2}[/tex]

3) The number obtained is 3 times the original number =

[tex]\frac{x + 30}{2} = 3x[/tex]

[tex]{x + 30} = 6x[/tex]

[tex]30 = 5x[/tex]

[tex]x = \frac{30}{5}[/tex]

[tex]x = 6[/tex]

                             

Is 2/3+4/5 a rational number

Answers

Answer:

Yes

Step-by-step explanation:

Yes. A rational number can be made by dividing two integers. When you add 2/3 and 4/5 you get the answer 22/15 and since both 22 and 15 are integers, and the answer of the problem is a simple fraction, 2/3+4/5 is in fact a rational number.

find the value of
[tex]3 log_{2}4[/tex]

Answers

Answer:

6

Step-by-step explanation:

log ₐ (aˣ) = x

3 log ₂ (4)

3 log ₂ (2²)

3 * 2

6

what is the midpoint of 2-3i and -4+6i
O2+31
-4-6i
0 -1+1.51
2-31

Answers

Add them up and divide the result by 2, and you'll have the midpoint.


((2-3i)+(-4+6i)) / 2 =
(-2+3i)/2 =
-1+1.5i

i know im dumb srry but help plz....​

Answers

The answer is A because 75 + 15 is 90

If two angles are complementary, then the

sum of their measures is 90 degrees.

We can find the m<B by taking 90 minus the measure of <A.

So here, we have 90 - 15 which is 75.

So m<A is 75 degrees.

Joel took out a car loan for 12000 he paid 4800 in interest at a rate of 8% per year how many year will it take him to pay off the loan.​

Answers

Answer:

  5 years

Step-by-step explanation:

Simple interest on a loan of P for t years at rate r per year is ...

  I = Prt

  4800 = 12,000(0.08)(t)

  4800/960 = t = 5

It will take Joel 5 years to pay off the loan.

What is the inverse of the function g(x)=-2(x-4)? g^-1(x)=___

Answers

Step-by-step explanation:

g(x) = y = 8 - 2x

(A) First transform the function in terms of x :

x = y - 8 / 2

(B) Replace x with y :

[tex] {g}^{ - 1} (x) = y = \frac{x}{2} - 4[/tex]

Someone please help me!!!!​

Answers

Answer:

Below.

Step-by-step explanation:

Left side = 2 cos^2 ( π/4 - A/2) - 1

= 2 ( cos π/4  cos A/2 + sin π/4  sin A/2)^2 - 1

Now sin π/4 and cos π/4 = 1 /√2 so:

= 2 ( 1/√2 cos A/2 + 1/√2 sin A/2)^2 - 1

= 2  * 1/2( cos^2 A/2 + sin^2 A/2 + 2 sin A/2 cos A/2) - 1

But cos^2 a/2 + sin^2 A/2 = 1 so we have:

2 * 1/2( 1 +  2sin A/2 cos A/2) - 1

= 1  + 2 sin A/2 cos A/2 - 1

=  2 sin A/2 cos A/2

Using the identity 2 sin A cos A = sin 2A

2 sin A/2 cos A/2 = sin A  = right side.

So left side = right side and the identity is proved.

Answer:  see proof below

Step-by-step explanation:

Use the Double Angle Identity:  cos 2A = 2cos²A - 1

Use the Difference Identity:  cos (A - B) = cosA · cosB + sinA · sinB

Use the Unit Circle to evaluate:  cos (π/2) = 0   &     sin (π/2) = 1

Proof  LHS → RHS

[tex]\text{Given:}\qquad \qquad \qquad \qquad 2\cos^2\bigg(\dfrac{\pi}{4}-\dfrac{A}{2}\bigg)-1\\\\\\\text{Double Angle Identity:}\quad \cos2\bigg(\dfrac{\pi}{4}-\dfrac{A}{2}\bigg)\\\\\\\text{Simplify:}\qquad \qquad \qquad \quad \cos\bigg(\dfrac{\pi}{2}-A\bigg)\\\\\\\text{Difference Identity:}\qquad \cos\dfrac{\pi}{2}\cdot \cos A+\sin \dfrac{\pi}{2}\cdot \sin A\\\\\\\text{Unit Circle:}\qquad \qquad \qquad 0\cdot \cos A+1\cdot \sin A\\\\\\\text{Simplify:}\qquad \qquad \qquad \qquad \sin A[/tex]

LHS = RHS:   sin A = sin A   [tex]\checkmark[/tex]

 

what does (x + 3)(x - 5)=

Answers

Your answer will be x2-2x-15

3х +3y-2х-у
I’m trying to combine like terms plz help

Answers

Answer:

1X+2Y

Step-by-step explanation:

3x - 2x = 1x

3y - 1y = 2Y

Answer:

3x+2y

Step-by-step explanation:

Let's simplify step-by-step.

3x+3y−y

=3x+3y+(−y)

Combine Like Terms:

=3x+3y+(−y)

=(3x)+(3y+(−y))

=3x+2y

Answer:

=3x+2y

HOPE THIS HELPS!!!!!! :)

<333333

If line a has a greater slope than line b, is line a steeper than line b? Explain, giving examples to support your answer. ( PLEASE HELP)

Answers

Answer:

No a greater slope is not always steeper

Step-by-step explanation:

If line A has a slope of 10 and line B has a slope of 6. The slope of line A will definetely be steeper than line B. In a negative slope, if line A's slope is -20 and line b's slope is 5 the line A will be steeper even though it is actually less than 5.

write the verbal sentence as an equation. let y represent the number

the difference of 7 and the quotient of a number and 6 is -150​

Answers

Answer:

Marcus is picking songs to play during a slideshow. The songs are each 3\dfrac123  

2

1

​  

3, start fraction, 1, divided by, 2, end fraction minutes long. The slideshow is 31\dfrac1231  

2

1

​  

31, start fraction, 1, divided by, 2, end fraction minutes long.

Step-by-step explanation:

Hi there, can anyone help me with this question?

A bag contains 1p, 2p and 5p coins. 2/5 of the bag are 2p coins. There are twice as many 1p coins than 5p coins in the bag. There are 630 coins in total. Work out the number of 5p coins in the bag. ​

Answers

Answer: 126 5p coins

Step by step explanation:
1p+2p+5p = 630
2p= 2/5 of 630
2p= 252
1p= 2( 5p)
630 - 252 = 378
378/3= 126= 5p
378-126= 252 = 1p
252+252+126= 630
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