Friday

July 25, 2014

July 25, 2014

Posted by **lilly** on Wednesday, March 27, 2013 at 1:15am.

f^-1(x)=

I haven't one clue how to do this...help me pleaaaase someone!

- math -
**Reiny**, Wednesday, March 27, 2013 at 7:46amlet y = (2x+8)/(3x-7) , notice the brackets are essential

step1: interchange the x and y variables to form the initial inverse.

x = (2y+8)/(3y-7)

step: solve this new equation for y

3xy - 7x = 2y+8

3xy - 2y = 7x + 8

y(3x - 2) = (7x + 8)

y = (7x + 8)/(3x - 2)

f^-1 (x) = (7x + 8)/(3x - 2)

test with some value of x, say x = 3

f(3) = 14/2 = 7

f^-1 (7) = should get 3 back ..

= (49+8)/(21-2) = 57/19 = 3 , looks ok

**Related Questions**

Algebra-One to one function - Could you please check my answers and help me with...

Algebra Help Inverse One-to-one - Did I do this right? Problem: If the ...

college alg - the function f(x)=6x+9/3x-7 is one to one. find its inverse and ...

algebra - 1. the function f(x)=6x/3x-5 is one to one. find its inverse and check...

Pre-Calc - Does y=1/x have an inverse? It is a one-to-one function, so it should...

Math(Please check) - The following function is one-to-one; find its inverse f(x...

Trigonometry - Having trouble with true/false questions in Trigonometry. They ...

Trigonometry - Having trouble with true/false questions in Trigonometry. They ...

Pre-Calculus - The function f(x)= x^4 is not one-to-one. Find a suitable ...

Algebra(1st one was typo) - The function f(x)=x^3 +1/4 x −1^4 is a ...