Find the inverse of the function f(x) = 4x − 28

Question

anonymous · Answer

wouldnt the inverse just be the same function with an inverse of slope?

anonymous · Answer

let y=f(x) so we can write it as:

y = 4x - 28   

now switch the x and the y... then solve for y...

anonymous · Answer

that will give you the inverse of f...

anonymous · Answer

I guess im right too. My way is easier just inverse the slope 
The slope is 4
the inverse is -1/4

anonymous · Answer

replace and you have the answer.

anonymous · Answer

well not not really

anonymous · Answer

@romero what about the intercept?

anonymous · Answer

it is not right

anonymous · Answer

Prove it

anonymous · Answer

$$f(x) = 4x − 28$$ function says 
a) multiply by 4
b) subtract 28

inverse says
a) add 28
b) divide by 4

write is as 
$$f^{-1}(x)=\frac{x+28}{4}=\frac{1}{4}x+7$$ a line with slope $\frac{1}{4}$ not $-\frac{1}{4}$

anonymous · Answer

Gotcha bro I was looking for the perpendicular line.

anonymous · Answer

Sorry

anonymous · Answer

y = 4x - 28

y - 28 = 4x

(y - 28) / 4 = x

now substitute place of x and y

y^-1 = (x-28) /4 = x/4 - 7