need help with precalulcus hw its due soon

Question

Let 

Answer 1

y=5-x, switch x and y to get

x=5-y, solve for y

y=5-x

surprise, f(x) is its own inverse = f^-1(x)

the slope = -1 and -1 is the inverse of -1

check it by letting x = say 2

then f(2) = 5-2 = 3

f^-1(3) = 5-3 = 2. You started with 2 and ended with 2

an inverse function sends you back to where you started.

Graph them. they are symmetric about y=x, the 45 degree line

they are the same line perpendicular to y=x