f(x)=(x-5)\(x+5) Find the inverse.

Question

f(x)=(x-5)\(x+5)  Find the inverse.

anonymous · Answer

to find the inverse of a function, dont you switch all the Ys and Xs and then solve for Y?

anonymous · Answer

yes but i dont know how to solve (y-5)/(y+5)

anonymous · Answer

-5(x+1)/(x-1)

anonymous · Answer

im pretty sure you need to solve for x first then switch Xs with Ys.. but i still dont know how to do that

anonymous · Answer

y = (x-5)/(x+5)

x = (y-5)/(y+5)
x (y+5) = y - 5
xy + 5x = y - 5
xy - y = -5x - 5
y (x - 1) = -5(x+1)

y = -5(x+1)/(x-1)

anonymous · Answer

thank you

anonymous · Answer

so i just cross multiply

anonymous · Answer

indeed, cross multiply, distribute out all the terms, then collect the y terms on one side.

factor out a y, and bring all the x's back to the other side.

it's kinda like... start out with everything separate, mash it all together, then separate it all out again

anonymous · Answer

got it.. u da man