Question

Find the inverse of f(x)=4x-3/2 when x=30

Answer 1

f of x is teckannly y so think of (fx) is another name for y

Answer 2

I have trouble with the fraction part. How do I get rid of the fraction?

Answer 3

let me see the fraction please

Answer 4

4x-3/2

Answer 5

3 devided by2

Answer 6

From what I know, I would insert 30 to x making it to 4(30)-3/2. Seems hard, but looks easy.

Answer 7

so i substitute 30 for x after I get the inverse?

Answer 8

Then u evaluate frm there.

Answer 9

Yes beuase x=30 in thi case.

Answer 10

when i am finding the inverse I get stuck on how to isolate the y variable, because it ends up in a fraction.

Answer 11

Th inverse when factoring js multiplying.

Answer 12

so i just multiply the fraction to get rid of it?

Answer 13

\(\bf f(x)=y=4x-\cfrac{3}{2}\qquad inverse \implies x= 4y-\cfrac{3}{2}\\ \quad \\ \quad \\
x= 4y-\cfrac{3}{2}\implies x+\cfrac{3}{2}=4y\implies \cfrac{\left(x+\frac{3}{2}\right)}{4}=y\\ \quad \\
\cfrac{x}{4}+\cfrac{\frac{3}{2}}{4} = y\implies \cfrac{x}{4}+\cfrac{3}{2}\cdot \cfrac{1}{4} = y\implies \cfrac{x}{4}+\cfrac{3}{8} = y = f^{-1}(x)\)

Answer 14

The fraction is set up like this in the problem

Answer 15

how would i find the inverse of that?

Answer 16

Yes you multiply

Answer 17

\(\bf f(x)=y=\cfrac{4x-3}{2}\qquad inverse \implies x= \cfrac{4y-3}{2}\\ \quad \\ \quad \\
2x = 4y-3\implies 2x+3 = 4y\implies \cfrac{2x+3}{4} = y = f^{-1}(x)\)

Answer 18

OOh, I see it now XD thnx!

Answer 19

yw