inverse function Q (1 Viewer)

[RishBonjour]

v) Assume x=N, when N is not in the domain chosen in part ii) but still in the domain for f(x)
find f^-1(f(N))

f(x) = x+1/x
inverse = x/2 +1/2(x^2-4)^(1/2)

domain found in part ii is x>=2

I've seen a similar question before in success one, but that was a parabola. not sure how to get this.

 

[Timske]

What is your question? Finding the inverse of f(x) = x+(1/x) ?

 

[RishBonjour]

v) Assume x=N, when N is not in the domain chosen in part ii) but still in the domain for f(x)
find f^-1(f(N))

thats the question.

its similar to this :
http://community.boredofstudies.org/showthread.php?t=283792&highlight=inverse+functions

similar to the question Aysce asked - i understand the symmetry there. but this one, I'm not sure




BTW: have 3u test tomorrow with this topic included. so please try! Or I will fail so hard

 

[Sanjeet]

v) Assume x=N, when N is not in the domain chosen in part ii) but still in the domain for f(x)
find f^-1(f(N))

thats the question.

its similar to this :
http://community.boredofstudies.org/showthread.php?t=283792&highlight=inverse+functions

similar to the question Aysce asked - i understand the symmetry there. but this one, I'm not sure




BTW: have 3u test tomorrow with this topic included. so please try! Or I will fail so hard

Your question is extremely unclear, but I'll have a go

 

[RishBonjour]

Question attached.

 

[bleakarcher]

x+(1/x)=N+(1/N)
Nx^2+N=(N^2+1)x
Nx^2-(N^2+1)+N=0
x=(N^2+1)+/-sqrt[(N^2+1)^2-4N^2] /2N
x=(N^2+1)+/-sqrt[(N^2-1)^2] /2N
x=(N^2+1)+/-(N^2-1) /2N
x=N or N^2+1-(N^2-1) /2N
x=N or 1/N
Hence, f(N)=f(1/N). Since N<1, 1/N>1 and therefore lies in the domain x>=1.
=> f^(-1)[f(N)]=f^(-1)[f(1/N)]=1/N

 

[Chowder_Head]

x+(1/x)=N+(1/N)
Nx^2+N=(N^2+1)x
Nx^2-(N^2+1)+N=0
x=(N^2+1)+/-sqrt[(N^2+1)^2-4N^2] /2N
x=(N^2+1)+/-sqrt[(N^2-1)^2] /2N
x=(N^2+1)+/-(N^2-1) /2N
x=N or N^2+1-(N^2-1) /2N
x=N or 1/N
Hence, f(N)=f(1/N). Since N<1, 1/N>1 and therefore lies in the domain x>=1.
=> f^(-1)[f(N)]=f^(-1)[f(1/N)]=1/N

wrong

 

[bleakarcher]

wrong

How you been goodwin?

 

[krispykareem]

Yeah buddy i was like who's that chick in the DP and realised it was you LOL!

 

[RishBonjour]

Yeah buddy i was like who's that chick in the DP and realised it was you LOL!

AHAHAHAHHAH KRISPY!!!

get off bos. go fishing

 

[Fus Ro Dah]

View attachment 25735



v) Assume x=N, when N is not in the domain chosen in part ii) but still in the domain for f(x)
find f^-1(f(N))

f(x) = x+1/x
inverse = x/2 +1/2(x^2-4)^(1/2)

domain found in part ii is x>=2

I've seen a similar question before in success one, but that was a parabola. not sure how to get this.

From where did you get this question? it looks exactly like a past HSC Q7.