156k views
4 votes
What is the inverse of the function g(x) =-3x+8

User Sobiaholic
by
7.9k points

2 Answers

5 votes
Hi!
To find the inverse, first we express your function as:

y = 3x - 8

Then, we interchange x and y variables:

x = 3y - 8

From there, we isolate y:

x + 8 = 3y

x/3 + 8/3 = y

Then, the inverse, g(x) = (x+8)/3.

We can check this by getting g(f(x)):
(f(x) + 8)/3 = (3x - 8 + 8)/3 = 3x /3 = x.

This is correct by the definition of the inverse function.

You can also think about the inverse as a "reverse function", so for example, in f(x) = 3x-8, x is multiplied by 3, then 8 is subtracted from it.
If we are to go from f(x) to x, we first add 8 (to reverse the subtraction), then divide by 3 (to reverse the multiplication).
This means g(y) = (y+8)/3, the same answer.

Hope this helps
User Circle B
by
6.9k points
4 votes

Answer:


g^(-1) (x)=-(x)/(3) +(8)/(3)

Explanation:

To find the inverse, interchange the variables and solve for y.

=
g^(-1) (x)=-(x)/(3) +(8)/(3)

User ErlVolton
by
7.2k points