Question

Let f(x) = 7x – 13. Find f–1(x).

Answer 1

x+3/7

Answer 2

hope that helps

Answer 3

replace the function notation with y
y = 7x – 13
exchange the positions of the x and y variables
x = 7y - 13
then solve for y
x+13 = 7y
dividing by 7\[y=\frac{x+13}{7}\]or\[f ^{-1}(x)=\frac{1}{7}x-\frac{13}{7}\]

Answer 4

Note: I made a minus sign error on my last line; it is supposed to be +13/7 (se it is correct in the second to last algebraic line). correct is\[f ^{-1}(x)=\frac{1}{7}x+\frac{13}{7}\]

Answer 5

You are aware that inverse functions are symmetric about the line y=x, here is that relationship