Functions

[FrozenDragon427]

Can someone help me with this?

 

[tkhunny]

Have you considered constructing f(f(x))?

 

[FrozenDragon427]

Have you considered constructing f(f(x))?

No, I haven't

 

[pka]

If \(f(x)=\dfrac{1}{x}\) then \(f\circ f(x)=\dfrac{1}{\frac{1}{x}}=~?\)

 

[FrozenDragon427]

So

If \(f(x)=\dfrac{1}{x}\) then \(f\circ f(x)=\dfrac{1}{\frac{1}{x}}=~?\)

If \(f(x)=\dfrac{1}{x}\) then \(f\circ f(x)=\dfrac{1}{\frac{1}{x}}=~?\)

So the answer will be..? X? Or 1?

 

[Sara.H]

So x=

 

[Sara.H]

So x=View attachment 21718

Now solve this equation.

 

[BraveHeart258]

what is \dfrac{1}{\frac{1}{x}}=~?\)

The answer is any some real number being the variable x. Thus, what is any that some real number?

 

[FrozenDragon427]

It will be part (d)- any real number, right? Forgive me if I sound stupid, but I haven't studied composite functions and I have a maths competition next week so I need to prepare for stuff like this.

 

[Sara.H]

It will be part (d)- any real number, right? Forgive me if I sound stupid, but I haven't studied composite functions and I have a maths competition next week so I need to prepare for stuff like this.

 

[Sara.H]

Part d is not correct. More think
Solve equation then give the answer.

 

[Sara.H]

Don't worry
I teach you composite function if you want.

 

[pka]

If \(f(x)=\dfrac{1}{x}\) then \(\large f\circ f(x)=\dfrac{1}{\frac{1}{x}}=~x\) thus
\(f(2)=\dfrac{1}{2}\) then \(f\circ f(2)=\dfrac{1}{\frac{1}{2}}=~2\)
\(f(-1)=\dfrac{1}{-1}=-1\) then \(f\circ f(-1)=\dfrac{1}{\frac{1}{-1}}=-1\)
\(f(1)=\dfrac{1}{1}=1\) then \(f\circ f(1)=\dfrac{1}{\frac{1}{1}}=~1\)

 

[Steven G]

what is \dfrac{1}{\frac{1}{x}}=~?\)

The answer is any real number being the variable x. Thus, what is any real number?

Can you please not give out answers on this forum. We prefer that the student figures out their own answers with our help. Besides your answer is not correct. Most real numbers do not equal their reciprocal.

 

[BraveHeart258]

Can you please not give out answers on this forum. We prefer that the student figures out their own answers with our help. Besides your answer is not correct. Most real numbers do not equal their reciprocal.

Okay, you are right.

 

[Sara.H]

Can you please not give out answers on this forum. We prefer that the student figures out their own answers with our help. Besides your answer is not correct. Most real numbers do not equal their reciprocal.

Why is my answer iincorrect ?

 

[Sara.H]

Why is my answer iincorrect ?

Sorry, I did not know the law of the site.

 

[firemath]

Sorry, I did not know the law of the site.

Our guidelines and forum rules are listed here.