1.2, 3, 7.5, 18.75, ... which formula can be used to describe the sequence?


Asked by maham237 @ in Mathematics viewed by 360 People


1.2, 3, 7.5, 18.75, ...
Which formula can be used to describe the sequence?

f(x) = 1.2(2.5)x – 1
f(x) = 2.5(1.2)x – 1
f(x) = 1.2(2.5)x
f(x) = 2.5(1.2)x

Answered by maham237 @



It's geometric sequence:

a_1=1.2,\ a_2=3,\ a_3=7.5,\ a_4=18.75,\ ....

Calculate the common ratio:

r=\dfrac{a_{n+1}}{a_n}\to r=\dfrac{3}{1.2}=2.5

The explicit formula of geometric sequence:

a_n=a_1r^{n-1}\to f(x)=a_1r^{x-1}

Substitute:

a_1=1.2,\ r=2.5\\\\f(x)=1.2\left(2.5)^{x-1}

Answer: "f(x) = 1.2(2.5)x-1"


Similar Questions

1 3 6 10 sequence formula

Asked by maham237 @ in Mathematics viewed by 361 persons

Triangular numbers can be represented with equilateral triangles formed by dots. The first five triangular numbers are 1, 3, 6, 10, and 15. Is there a direct variation between a …

Solve using quadratic formula 2x 2 5x 3 0

Asked by admin @ in Math viewed by 359 persons

Find the roots of the equation 2x 2 – 5x + 3 = 0, by using quadratic formula.

Which formula best describes the amount an insurance

Asked by maham237 @ in Business viewed by 268 persons

Which formula best describes the amount an insurance company will pay you for your loss? a) Payment = Loss - Deductible b) Payment = Loss + Deductible c) Payment = …

How to use formula autocomplete in excel

Asked by maham237 @ in Computers And Technology viewed by 350 persons

How do you activate the Formula AutoComplete function of Excel 2016?

Find a formula for the nth term of the sequence

Asked by admin @ in Mathematics viewed by 264 persons

What is the nth term in the sequence: 4, 7, 12, 19, 28 Please show working out

The proper sequence used in recording a business transaction is

Asked by admin @ in Business viewed by 330 persons

The ten steps of the accounting cycle are presented below. Identify the correct order of the steps by placing the numbers 1 (first step) to 10 (last step) by each …

The proper sequence to use in solving 3x 2 60

Asked by maham237 @ in Mathematics viewed by 305 persons

is: divide by 3. add 2 add 2. divide by 3 multiply by 3. subtract 2 subtract 2. multiply by 3

Use the formula to evaluate the series 2 10 50

Asked by maham237 @ in Mathematics viewed by 300 persons

Use the formula to evaluate the series 2 - 10 + 50 -250 + ... a6 sn = a1(1-r^n) / 1-r

Find the sum of a finite geometric sequence from n = 1 to n = 7, using the expression −4(6)n − 1.

Asked by maham237 @ in Mathematics viewed by 311 persons

Find the sum of a finite geometric sequence from n = 1 to n = 7, using the expression −4(6)^n − 1. a. 111,325 b. 526 c. 782 d. -22,948

Use compass directions to describe the direction of the vector

Asked by maham237 @ in Mathematics viewed by 354 persons

How to find the nth term of a sequence formula

Asked by admin @ in Mathematics viewed by 299 persons

Find an equation for the nth term of the arithmetic sequence. 8, 6, 4, 2, ...

Using a cell address in a formula is known as

Asked by admin @ in Computer Science viewed by 312 persons

The cell address in a formula is also called

How can heredity be used to describe the real world

Asked by maham237 @ in Chemistry viewed by 341 persons

Most viewed questions in Mathematics


Unit 6 similar triangles homework 2 similar figures answer key

Asked by maham237 @ in Mathematics viewed by 18361 persons


All things algebra unit 7 polygons and quadrilaterals answer key

Asked by admin @ in Mathematics viewed by 8161 persons


Gina wilson all things algebra 2016 answer key unit 11

Asked by admin @ in Mathematics viewed by 5784 persons



Unit 1 geometry basics homework 4 angle addition postulate answers

Asked by maham237 @ in Mathematics viewed by 3936 persons


Unit 6 exponents and exponential functions homework 8 answer key

Asked by maham237 @ in Mathematics viewed by 3253 persons


The manager of a vacation resort believes that the ages

Asked by maham237 @ in Mathematics viewed by 2925 persons



What is 271 403 rounded to the nearest ten thousand

Asked by maham237 @ in Mathematics viewed by 2798 persons


Unit 1 geometry basics homework 3 angle relationships answer key

Asked by maham237 @ in Mathematics viewed by 2584 persons


Homework 2 parallelograms

Asked by maham237 @ in Mathematics viewed by 2503 persons



Why would a prism beat a sphere in a competition?

Asked by maham237 @ in Mathematics viewed by 2481 persons


John wants to send a letter to peter

Asked by maham237 @ in Mathematics viewed by 2464 persons


An artist sells a painting for 20.50 but uses 5.75

Asked by maham237 @ in Mathematics viewed by 2431 persons



Unit 4 congruent triangles homework 1 classifying triangles answer key

Asked by maham237 @ in Mathematics viewed by 2420 persons


Unit 4 congruent triangles homework 2 angles of triangles

Asked by maham237 @ in Mathematics viewed by 2076 persons


Compare the values of the 2s and 5s in 55220

Asked by maham237 @ in Mathematics viewed by 1794 persons