ALGEBRA 2

Given f(x) = the quantity of 4x plus 1, divided by 3, solve for f-1(3).

A. 2

B. 4

C. 6

D. 8

can somebody explain how to do this please?

Question

ALGEBRA 2

Given f(x) =  the quantity of 4x plus 1, divided by 3, solve for f-1(3).

A.  2

B.  4

 C. 6

 D. 8

can somebody explain how to do this please?

campbell_st · Answer

do you have the inverse function...?

anonymous · Answer

f(x) = $$\frac{ 4x+1 }{ 3 } solve for  f -1 (3)  $$

anonymous · Answer

yes this is a inverse function

campbell_st · Answer

no, that looks like the function itself.. 

are you asked to find 

$$f^{-1}(3)$$

anonymous · Answer

yes.

anonymous · Answer

I didn't know how to write the inverse on here

campbell_st · Answer

ok... this is what you need to do

swap x and y 

the original function is 

$$y = \frac{4x + 1}{3}$$

when you make the swap you get

$$x = \frac{4y + 1}{3}$$

to find the inverse, you need to make y the subject... 

does that make sense?

anonymous · Answer

yes this makes sense i've got that far already , im just confused on where to plug in the 3

campbell_st · Answer

ok... well you can plug it in straight away and say 

$$3 = \frac{4y + 1}{3}$$

and find the value of y

campbell_st · Answer

or the inverse is 

$$f^{-1}(x) = \frac{3x -1}{4}$$

now substitute x = 3