# Thread: search For f - 1

1. ## search For f - 1

Hey Guys Hope you are Fine , i need some Help with those numbers i got a lot of them

determine For f-1

1)f: x --> (radical) x ^ 2 x E R
2) f: x ---> x ^ 2 for x = and > 0
- X ^ 2 <0

3). f: x ---> sinx, x E R

4)f: x ---> x 2 / x-1, x # 1

5)f: x --> x ^ 2-4x 3 / x ^ 2-4x-5, s E] 5 + infinity[

6)Show that the function:
F: x --> x ^ 3-x, x E [1,3] admits a function reciproque

N.B: f-1 --->

2. Originally Posted by iceman1
Hey Guys Hope you are Fine , i need some Help with those numbers i got a lot of them

determine For f-1

1)f: x --> (radical) x ^ 2 x E R
2) f: x ---> x ^ 2 for x = and > 0
- X ^ 2 <0

3). f: x ---> sinx, x E R

4)f: x ---> x 2 / x-1, x # 1

5)f: x --> x ^ 2-4x 3 / x ^ 2-4x-5, s E] 5 + infinity[

6)Show that the function:
F: x --> x ^ 3-x, x E [1,3] admits a function reciproque

N.B: f-1 --->

to find $\displaystyle f^{-1}(x)$, if it exists. switch x and y and solve for y

example: if $\displaystyle f(x) = x + 1$, find $\displaystyle f^{-1}(x)$

since $\displaystyle y = x + 1$ for $\displaystyle f^{-1}(x)$, switch x and y

we get: $\displaystyle x = y + 1$

$\displaystyle \Rightarrow y = x - 1$

therefore, $\displaystyle f^{-1}(x) = x - 1$

now do the same for your questions