Problem 6
Let Tn be the nth triangular number, Qn be the nth square number and
Pn be the nth pentagonal number.
(a) Show that 3Pn = T3n-1.
(b) Show that Pn - Qn = Tn-1 and hence that P3n - 3Pn = Q3n.

Answers

Answer 1

It has been shown that [tex]3P_{n} =T_{3n-1}[/tex], [tex]3P_{n} =T_{3n-1}[/tex] and hence [tex]3P_{n} =T_{3n-1}[/tex].

Given: [tex]T_{n}[/tex] is the nth triangular number. [tex]Q_{n}[/tex] is the nth square number. [tex]P_{n}[/tex] is the nth pentagonal number.

To show:

[tex]3P_{n} =T_{3n-1}[/tex] [tex]P_{n} -Q_{n} =T_{n-1}[/tex] and hence [tex]P_{3n} -3P_{n} =Q_{3n}[/tex]

Triangular numbers are numbers formed by addition of consecutive natural numbers starting from 1. Square numbers are numbers formed by squaring natural numbers. Pentagonal numbers are numbers formed by distinct dots in a pattern of dots consisting of the outlines of regular pentagons with sides up to n dots, when the pentagons are overlaid so that they share one vertex.

The formula for each of them is given by:

[tex]T_{n}=\frac{n(n+1)}{2}[/tex]

[tex]Q_{n}=n^{2}[/tex]

[tex]P_{n}=\frac{3n^{2}-n}{2}[/tex]

(a).

Now, put [tex]n=3n-1[/tex] in [tex]T_{n}=\frac{n(n+1)}{2}[/tex] to get,

[tex]T_{3n-1}=\frac{(3n-1)(3n)}{2}[/tex]

[tex]T_{3n-1}=3\frac{n(3n-1)}{2}[/tex]

[tex]T_{3n-1}=3\frac{3n^{2}-n}{2}[/tex]

Put [tex]P_{n}=\frac{3n^{2}-n}{2}[/tex] in [tex]T_{3n-1}=3\frac{3n^{2}-n}{2}[/tex] to get,

[tex]T_{3n-1}=3P_{n}[/tex]

So, [tex]3P_{n}=T_{3n-1}[/tex]

(b).

Now,

[tex]P_{n}-Q_{n}=\frac{3n^{2}-n}{2}-n^{2}[/tex]

[tex]P_{n}-Q_{n}=\frac{3n^{2}-n-2n^{2}}{2}[/tex]

[tex]P_{n}-Q_{n}=\frac{n^{2}-n}{2}[/tex]

Put [tex]n=n-1[/tex] in [tex]T_{n}=\frac{n(n+1)}{2}[/tex] to get,

[tex]T_{n-1}=\frac{(n-1)(n-1+1)}{2}[/tex]

[tex]T_{n-1}=\frac{(n-1)n}{2}[/tex]

[tex]T_{n-1}=\frac{n^{2}-n}{2}[/tex]

Comparing [tex]P_{n}-Q_{n}=\frac{n^{2}-n}{2}[/tex] and [tex]T_{n-1}=\frac{n^{2}-n}{2}[/tex], we get,

[tex]P_{n}-Q_{n}=T_{n-1}[/tex]

Now, put [tex]n=3n[/tex] in [tex]P_{n}-Q_{n}=T_{n-1}[/tex] to get,

[tex]P_{3n}-Q_{3n}=T_{3n-1}[/tex]

As shown in part (a), [tex]T_{3n-1}=3P_{n}[/tex]

Put [tex]T_{3n-1}=3P_{n}[/tex] in [tex]P_{3n}-Q_{3n}=T_{3n-1}[/tex] to get,

[tex]P_{3n}-Q_{3n}=3P_{n}[/tex]

[tex]P_{3n}-3P_{n}=Q_{3n}[/tex]

So, [tex]P_{n}-Q_{n}=T_{n-1}[/tex] and hence [tex]P_{3n}-3P_{n}=Q_{3n}[/tex]

Learn more about these kinds of numbers here:

https://brainly.com/question/16642741


Related Questions

the measures of the angles of a triangle are shown in the figure. solve for x

Answers

Answer:

10

Step-by-step explanation:

First, we know that the angles of a triangle add up to 180 degrees. We can then sum up our angles as 90 (since it's a right triangle, represented by the square in the bottom left angle) +27+6x+3=180

90+27+6x+3=180

Add up left side

120+6x=180

Subtract 120 from both sides

6x=60

Divide both sides by 6

x=10

determine the equation of the circle graphed below .

( help pleasee )

Answers

Answer:

move the circle around that's how you co-ordinate

Step-by-step explanation:

Mrs. Malik ( my maths teacher ) helped me

Answer:

(x + 3)^2 + (y + 5)^2 = 4^2

Step-by-step explanation:

equation of a circle: (x - h)^2 + (y - k)^2 = r^2

(h,k) is the center and r is the radius

the center of this circle is (-3, -5) and the radius is 4

plug the numbers in

(x + 3)^2 + (y + 5)^2 = 4^2

hope this is good, havent done this unit in a while

is this linear, exponential, or quadratic?

Answers



Linear. Each increase of 1 in x means a decrease of 3 in y, so it has a consistent slope of -3

Which best describes the relationship between the line that passes through the points (-9, -7) and (-12, -2) and the line
that passes through the points (1,9) and (6, 6)?
A. same line
B. perpendicular
C. parallel
D. neither perpendicular nor parallel

Answers

Answer:

D

Step-by-step explanation:

y2 - y1 / x2 - x1

-2 - (-7) / -12 - (-9)

5/-3

= -5/3

y2 - y1 / x2 - x1

6 - 9 / 6 - 1

= -3/5



which pair is a pair of vertical angles?

Answers

Answer:

Angles that are directly across from each other

Step-by-step explanation:

Vertical angles are angles that are directly across from each other, forming an x. They always have the same degree

Find mZHFG if mZEFG = 2x + 52, mZEFH = 21°, and mZHFG = 1 + 31

Answers

Answer:

m<HFG = 31

Step-by-step explanation:

We can say that m<EFH + m<HFG = m<EFG because of angle addition postulate. Now, we can substitute the values of the angles in.

21 + x + 31 = 2x + 52

x + 52 = 2x + 52

x = 0

Now, we substitute x into the expression of m<HFG:

m<HFG = x + 31

m<HFG = 0 + 31

m<HFG = 31

What trig ratio would you use to solve for x?

O Cosine
O Tangent
O Sine

Answers

Answer: Cosine

This is because cosine involves the adjacent over hypotenuse

cos(angle) = adjacent/hypotenuse

In ΔQRS, the measure of ∠S=90°, SR = 12, RQ = 37, and QS = 35. What ratio represents the cotangent of ∠Q?

Answers

Answer:

35/12

tan Q = 12/35

so cotan Q = 35/12

Anita can exercise for 20 minutes on her lunch break and 30 minutes after work on her 5 work days. She exercises 35 minutes on the weekend. How many hours per week does Anita exercise? 4 hours per week 4 hours per week 4 hours per week 5 hours per week

Answers

Answer:

4 3/4 hours per week

Step-by-step explanation:

i need help asap …………..

Answers

Step-by-step explanation:

since the radii are all congruent, you can just draw a new one and call it KP. KP = 5 because all radii are congruent. By doing this, point P is now a tangent.

Area of circle =
A) 36 pie square units
B) 6 pie square units
C) 12 pie square units

Answers

Answer:

36 pi

Step-by-step explanation:

The radius is 6

A = pi r^2

A = pi 36

Answer:

Area of circle = 36 π square unit

Step-by-step explanation:

To calculate area of circle simplify formula area of circle . we have given radius of circle which is 6.

Area of circle = π × r²

where,

r is the radius of circle

substitute the value

Area of circle = π × ( 6 ) ²

expand the exponent

Area of circle = π × 36

multiply

Area of circle = 36 π square unit

If U = {x: X € N, 1 < × < 15)
A= {x:x is multiple of 2}
B = {x: x is multiple of 3
C = {x: x is multiple of 5)
verify the following
(a) A(BnB)=(AUB)(AUB)
(b) An(BUC)=(AnB)u(Ang)
(c) AU(BUC)=(AUB)U(AUC)​

Answers

Answer:

Step-by-step explanation:

Given:

U = {x: X € N, 1 < × < 15) = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}

A = {2,4,6,8,10,12,14}

B = {3,6,9,12,15}

C = {5,10,15}

(a) Verify A(BnB)=(AUB)(AUB)

A U (B n B)

=  {2,4,6,8,10,12,14} U (  {3,6,9,12,15} n  {3,6,9,12,15} )

=  {2,4,6,8,10,12,14} U {3,6,9,12,15}

=  {2,3,4,6,8,9,10,12,14,15}

( A U B) n (A U B)

= {2,3,4,6,8,9,10,12,14,15} n {2,3,4,6,8,9,10,12,14,15}

= {2,3,4,6,8,9,10,12,14,15}

Therefore

A U (B n B)  =  ( A U B) n (A U B)

verifies

(b) Verify An(BUC)=(AnB)u(AnC)

A n ( B U C)

=  {2,4,6,8,10,12,14} n ( {3,6,9,12,15} U {5,10,15} )

=  {2,4,6,8,10,12,14} n {3,5,6,9,10,12,15}

= {6,10,12}

( A n B ) U ( A n C )

= ( {2,4,6,8,10,12,14} n {3,6,9,12,15} ) U ( {2,4,6,8,10,12,14} n {5,10,15} )

= {6,12} U {10}

= {6,10,12}

Therefore

A n ( B U C) = ( A n B ) U ( A n C )

verifies

(c) Verify AU(BUC)=(AUB)U(AUC)​

AU(BUC)

=  {2,4,6,8,10,12,14}U{3,6,9,12,15}U{5,10,15}

= {2,3,4,5,6,8,9,10,12,14,15}

(AUB)U(AUC)​

=  ({2,4,6,8,10,12,14}{3,6,9,12,15})U({2,4,6,8,10,12,14}U{5,10,15})

= {2,3,4,6,8,9,10,12,14,15}U{2,4,5,6,8,10,12,14,15}

= {2,3,4,5,6,8,9,10,12,14,15}

Therefore

AU(BUC)=(AUB)U(AUC)​

verifies

Of the songs in Jessica's music library, 7/8 are rock songs. Of the rock songs, 5/8 feature a guitar solo. What fraction of the songs in Jessica's music library are rock songs that feature a guitar solo?

*no scamming links are allowed or else I’ll have to report you* .

Answers

Answer:

ok so we know 7/8 of them are rock songs and of those songs 5/8 are solos so if we multiple this we get 35/64

Hello, someone knows the answer, could you help me thank you please ;(

Answers

Answer:

22/33and 14/21

1/3

mark as brainiest please

Consider a single spin on the spinner shown below. A circle is split into sections 1, 2, 4, and 3. A spinner is pointing at number 2. Sections 1 and 2 are shaded. Which events are mutually exclusive? Check all that apply. landing on an unshaded portion and landing on 2 landing on a shaded portion and landing on 3 landing on a shaded portion and landing on an even number landing on an unshaded portion and landing on a number greater than 3 landing on a shaded portion and landing on an unshaded portion

Answers

Answer:

The answer is "Options A, B, and E represent mutually exclusive events".

Step-by-step explanation:

Two occurrences that can happen immediately called mutually incompatible. Let's now glance at our options and figure out where the statements are mutually incompatible events.

In Option A: You could see that landing on an unwanted portion and arriving on 2 are events that are locally incompatible, even as undesirable portion contains 3 and 4, and 2 were shaded.

In Option B: Arriving on a shaded part and falling on 3 are also mutually incompatible because there are 3 on a windows azure.

In Option C: A darkened portion and an increasing amount can land while 2 would be an even number as well as on the shaded portion. That number is very much the same.

In Option D: At the same time as 4 is greater than 3 and it is situated upon an undistressed section, landing and attracting a number larger than 3 can happen.

In Option E: Landing on a shaded part and landing on even a shaded part is an excluding event, since shaders may either be shaded or unlit.

Answer:

first, second and fifth

Step-by-step explanation:

edge 2021

What is the complement that is given from the angle?

Answers

Answer:

59 is the complement of the angle ABC.

Step-by-step explanation:

complement is what adds to that angle to make it 90 degrees. 31+59=90

Answer:

59 is the complement of the angle ABC.

Step-by-step explanation:

Help me please the numbers I am using is 1,2,2,3,4,5,6,7,8,9

Answers

Answer:

2, 4.5 and 8

Step-by-step explanation:

(1)

The mode is the number which occurs most often , then

mode = 2

(2)

The median is the middle value of the numbers arranged in ascending order. If there is no exact middle value then it is the average of the numbers either side of the middle.

1,  2,  2,  3,  4,  5,  6,  7,  8,  9

                     ↑ middle

median = [tex]\frac{4+5}{2}[/tex] = [tex]\frac{9}{2}[/tex] = 4.5

(3)

The range is the difference between the largest and smallest values

range = 9 - 1 = 8

Answer:

If your numbers are 1,2,2,3,4,5,6,7,8,9

Step-by-step explanation:

1.Mode is the data in the value which occurs most frequently.

The mode of your number is 2 cause its frequency is 2 times and its known as bimodal.

2.Median is the middle value when the data is arranged in order of size.

The median of your number is

1,2,2,3,4,5,6,7,8,9

4+5=9

2

=4.5 So,the median is 4.5

3.Range is the difference between the highest value and the smallest value of a given data.

Your range is

Range=9-1=8

I THINK IT MIGHT HELP YOU!!!

the sum of the 13th square number and the 4th cube number?

Answers

Answer:

13th square number+4th cube number=233

Step-by-step explanation:

[tex]13^{2} +4^{3}[/tex]=233

The value of the sum of the 13th square number and the 4th cube number will be 223.

What is the value of the expression?

When the relevant components and basic processes of a numerical method are given values, the expression's result is the result of the computation it depicts.

The act of converting a specified statement into an expression or equation is known as a sentence-to-equation transformation.

The sum of the 13th square number and the 4th cube number. Then the numerical expression is given as,

⇒ (13)² + (4)²

Simplify the numerical expression, then we have

⇒ (13)² + (4)³

⇒ 169 + 64

⇒ 223

The value of the sum of the 13th square number and the 4th cube number will be 223.

More about the value of the expression link is given below.

https://brainly.com/question/23671908

#SPJ2

-6x + 7y = 9
2x - 2y = 4
Solve for x and y

Answers

Answer:

x = 23 , y = 21

Step-by-step explanation:

-6x + 7y = 9 -- (1)

2x - 2y = 4 -- (2)

(2) x 3 : 6x - 6y = 12 -- (2)'

(1) + (2)' : y = 21 -- (3)

Subtituting (3) into (2),

2x - 42 = 4

2x = 46

x = 23 -- (4)

According (3) and (4),

x = 23 , y = 21

If this helps you, please give brainliest!

The perimeter of a rectangle with width, x cm and length, y cm is 82cm. If the length of a rectangle is 15 cm longer than its width, calculate the length and the width of the rectangle.

Answers

Answer:

Here, let width of the rectangle be x cm then length becomes xcm+5cm(length of the rectangle is 5cm longer than width)

Now, we know

Perimeter(p)=2(length+width)

40= 2(x+5+x)

40=2(2x+ 5)

40/2=2x+5

20=2x+5

20–5=2x

15/2=x

x=7.5

Now,

length=x+5=7.5+5=12.5cm

width=x=7.5cm

Therefore length is 12.5cm and width is 7.5cm.

If a tree cast a 3.5 foot shadow at the same time is 6 foot tall women cast a shadow measuring 13.8 feet what would be the height of the tree

Answers

Answer:

1.522 ft tall

Step-by-step explanation:

divide 13.8 by 6ft and you would get 2.3

the height of the object multiplied by 2.3 would get you the shadow so, to get the original height from the shadow, just divide by 2.3.

PLEASE HELP, I AM MARKING BRAINLEST, dont forget to show work please :)

Answers

Value of g(-2) = -8

hope it helps you.....

Answer:

-12

Step-by-step explanation:

-4(-2)^2 -3(-2) -2

-4(4) +6 -2

-16 +6 -2

-12

Can someone help i'm struggling!

Answers

Answer:$499.20

Step-by-step explanation:

12% of 960 = 115.20

115.20 x 4

= 460.80

960 - 460.80

= $499.20

Answer:

Step-by-step explanation:

960(.88)^4 = $575.71

answer is A

Choose an equation of a line through the point (-4, 1) perpendicular to y=−12x+3.

Answers

Answer:

[tex]y = \frac{1}{12}x + \frac{4}{3}[/tex]

Step-by-step explanation:

slope of perpendicular line: m = [tex]\frac{1}{12}[/tex]

solve for b:

[tex]1 = \frac{1}{12}(-4) + b[/tex]

solve parenthesis:

[tex]1 = -\frac{1}{3}+b[/tex]

add [tex]\frac{1}{3}[/tex] to both sides:

[tex]b = \frac{4}{3}[/tex]

final equation: [tex]y = \frac{1}{12}x + \frac{4}{3}[/tex]

Solve for x
11^x = 11^4* 11^5

Answers

Answer:

x = 9 hope i helped and sorry if I'm wrong :)

The value of the square root of 42

Answers

[tex]\sqrt{42} =6.480740698/\sqrt{42}[/tex]

Answer:

6.4807 Step-by-step explanation:

The square root of 42 is 6.4807.

A function is shown in the table at the right. Find the rate of change over the interval 1≤ x≤ 3 .

Answers

Given:

The table of values of a function.

To find:

The rate of change of the function over the interval [tex]1\leq x\leq 3[/tex].

Solution:

The rate of change of a function over the interval [a,b] is:

[tex]m=\dfrac{f(b)-f(a)}{b-a}[/tex]

The rate of change of the given function over the interval [tex]1\leq x\leq 3[/tex] is:

[tex]m=\dfrac{f(3)-f(1)}{3-1}[/tex]

From the given table, it is clear that the value of the function is 4 at [tex]x=1[/tex] and 16 at [tex]x=3[/tex].

[tex]m=\dfrac{16-4}{2}[/tex]

[tex]m=\dfrac{12}{2}[/tex]

[tex]m=6[/tex]

Therefore, the rate of change of the given function over the interval [tex]1\leq x\leq 3[/tex] is 6.

Please help ASAP
Will give Brainliest
Want explanation

Answers

Answer:

1.73 or 3+√6/√3+√2

Step-by-step explanation:

1. Simplify the Numerator...3+ the square root of 6 cannot be simplified, so the answer is 5.45

2. Simplify the Denominator.

[tex]17 \sqrt{3} - 2 \sqrt{4} \sqrt{4} \sqrt{2} + 3 \sqrt{9} \sqrt{2} - 4 \sqrt{4} \sqrt{4} \sqrt{3} = 17 \sqrt{3} - 8 \sqrt{2} + 9 \sqrt{2} - 16 \sqrt{3} = \sqrt{3} + \sqrt{2} = 3.15[/tex]

3. Divide. 5.45/3.15= 1.73

Quick please someone help!!! This is my last day to turn in work and if I don’t I’m getting my phone, tv and privileges to go hang out with friends taken away. I would really like to keep my friends so please help me!!! :,(

Answers

Answer:

angle MPN = 79°

angle MPQ = 101°

Please help fast it’s subtraction

Answers

Answer:

17

220

Result in decimals: 0.077272727272727

Step-by-step explanation:

Answer:

[tex]7\frac{17}{220}[/tex]

Step-by-step explanation:

[tex]9\frac{8}{11} -2\frac{13}{20}=\\[/tex]

[tex]9\frac{160}{220} -2\frac{143}{220}=[/tex]

[tex]=7\frac{17}{220}[/tex]

Hope this helps

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