Algebra II help plz- WILL FAN & MEDAL
Can someone walk me through how to find the inverse of a function??

Given the function f(x) = 6(x+2) − 3, solve for the inverse function when x = 21.

−45

0

2

63

Question

Algebra II help plz- WILL FAN & MEDAL
Can someone walk me through how to find the inverse of a function??

Given the function f(x) = 6(x+2) − 3, solve for the inverse function when x = 21. 

 −45 

 0 

 2 

 63

imstuck · Answer

To find the inverse function, the first thing you have to do is switch the x and y and solve for the new y.  Then fill in the 21 for the new x.  Like this:

imstuck · Answer

$$f(x) = y$$so$$y=6(x+2)-3$$Distribute and do the math to get$$y=6x+9$$

imstuck · Answer

now switch the x and the y and solve for the new y.

imstuck · Answer

$$x=6y+9$$Subtract 9 from both sides now to get$$x-9=6y$$and divide both sides by 6 to get the y alone.$$\frac{ x-9 }{ 6 }=y$$

imstuck · Answer

Now fill in the x with 21 and solve for y.  What do you get when you do that?

ericanoel912 · Answer

y=2!!

ericanoel912 · Answer

Thank you so much! My Algebra II teacher couldn't explain it that well :)  You're awesome!