Question

Another functions questions?

Answer 1

Let f(x) = 2x + 2. Solve f-1(x) when x = 4.

1

3

4

10

Answer 2

2x + 2
2 (4) + 2
8 + 2
10

But I don't get what the f-1(x) is so I don't know if im right or not?

Answer 3

@Mokeira

Answer 4

it simply means inverse

Answer 5

so I'm right? inverse = opposite doesn't it?

Answer 6

or its 1 actually?

Answer 7

This is how you do it
\[2x+2=\frac{ 1 }{ 2 }x+2\]
you inverse the 2 that has x

Answer 8

then substitute

Answer 9

hope you get what I am trying to say

Answer 10

@CrazyTurtle483

Answer 11

sorry i had to go get dogs in

Answer 12

yea i kinda do it's kind of confusing

Answer 13

when i do it on paper i get 1

Answer 14

basically it means inverse the value that has x...in this case, 2x, we inverse 2

Answer 15

you should get 4

Answer 16

\[\frac{ 1 }{ 2 }x+2=(\frac{ 1 }{ 2 }\times 4)+2\]
\[=2+2\]
=4

Answer 17

Let f(x) = 2x + 2. Solve f-1(x) when x = 4.

f(x) returns a number. call it y.
\(f^{-1}(y)\) takes the out of f(x), and returns the x

Answer 18

in other words
\[ f^{-1}(4) \] means the output of f(x) = 4
and we want to find x.
f(x) = 2x + 2
4 = 2x+2
solve for x

add -2 to both sides: 4-2 = 2x +2-2
2= 2x
divide both sides by 2
1= x
1 is the answer