Question

MT&A uses the function f(x)=475-15x-15x.to depreciate smart phones. where f represents the value of smart phone and x represents the number of months since its purchase. a) find f^-1 and explain what it represents in this situacions When will the deprecated value of smart phone be less than $100.00? what does x represent in f^-1(x) =30? What is the value of x? Graph f(x) and f^-1 (x) on the same coordinate

Answer 1

Find the answers in the explanation

Explanation:

The given function is

f(x)=475-15x

A.) To find f^-1 and explain what it represents in this situacions, let f(x) = y. That is,

Y = 475 - 15x

Interchange y and x and make y the subject of formula

X = 475 - 15y

-15y = x - 475

Y = 475/15 - x/15

Y = (475 - x) / 15

Therefore,

f^-1(x) = (475 - x) / 15

If the function depreciates the smartphone, then, the inverse function will appreciate it.

When will the deprecated value of smart phone be less than $100.00

Substitute 100 for f(x) and find x

100 = 475 - 15x

-15x = 100 - 475

-15x = - 375

X = 375/15

X = 25

Therefore, the deprecated value of smart phone be less than $100.00 in the next 26 months.

what does x represent in f^-1(x) =30?

X represent the number of months for the smartphone appreciations

What is the value of x?

Substitute the inverse function for 30 and make x the subject of formula in the equation

f^-1(x) = (475 - x) / 15

30 = (475 - x) / 15

Cross multiply

450 = 475 - x

X = 475 - 450

X = 25 months

Graph f(x) and f^-1 (x) on the same coordinate