Thread: How to find the inverse of a function?

i have got this question and am a little confused..can u plz solve...(plz provide all steps)...

i) I=130+ (0.25).(Y)


ii) Y=(4).(I) -500

I(Y) = 130 + 0.25Y

Make Y the subject of formula and then, 'change' the variables, that is replace I by Y and Y by

If that's what you are asking...

4*(I(Y)-130) = Y

so =4*(Y-130)

Yep.

Try the other one now.