Question

For a certain function f = f(x), we know that f is proportional to x and that the constant of proportionality is 20. Find a formula for f.

a) f(x) = 20x

b) f(x) = 20

c) f(x) = x+20

f(x) = 20 x^20

Answer 1

Option a - f(x)=20x

Explanation:

Given : For a certain function f = f(x), we know that f is proportional to x and that the constant of proportionality is 20.

To Find : A formula for f ?

Solution :

We have given that,

f is proportional to x i.e.
`f\propto x`

This implies
`f=kx`

Where, k is the proportionality constant

The constant of proportionality is 20.

So,
`f=20x`

On comparing with, f = f(x)

`f=f(x)=20x`

Therefore, The formula of f is
`f=f(x)=20x`

So, Option a is correct.