Ask your own question, for FREE!
Mathematics 12 Online
OpenStudy (anonymous):

FUNCTION QUESTION

OpenStudy (anonymous):

OpenStudy (anonymous):

no more info about f?

OpenStudy (anonymous):

Nope. That's all they give.

OpenStudy (anonymous):

maybe like it's linear or something?

OpenStudy (anonymous):

If I do that, then I get \[f(\frac{1}{1 - x}) + 2f(\frac{1 - x}{-x}) = \frac{1}{1 - x}\]

OpenStudy (anonymous):

sorry i made a little mistake wait a sec

OpenStudy (zarkon):

look at x=2, x=1/2 and x=-1

OpenStudy (anonymous):

f(2) + 2f(-1) = 2 f(1/2) + 2f(2) = 1/2 f(-1) + 2f(1/2) = -1 f(2) + 2f(-1) = 2 -2(f(-1) + 2f(1/2) = -1) f(2) + 2f(-1) = 2 -2f(-1) - 4f(1/2) = 2 f(2) - 4f(1/2) = 4 f(1/2) - 4f(-1) = -4 f(2) - 4f(1/2) = 4 4f(1/2) - 16f(-1) = -16 f(2) - 4f(1/2) = 4 f(2) = -12 + 16f(-1) f(2) = -12 + 16(2 - f(2)) f(2) = -12 + 32 - 16f(2) f(2) = 20 - 16f(2) 17f(2) = 20 f(2) = 20/17 That's what I got :/

OpenStudy (zarkon):

hmmm...not what i got

OpenStudy (zarkon):

\[f(2)+2f(-1)=2\] \[f(1/2)+2f(2)=1/2\] \[f(-1)+2f(1/2)=-1\] \[f(2)+2f(-1)=2\Rightarrow\frac{1}{2}f(2)+f(-1)=1\] \[f(1/2)+2f(2)=1/2\Rightarrow 2f(1/2)+4f(2)=1\] add the two equations on the right \[\frac{1}{2}f(2)+f(-1)+2f(1/2)+4f(2)=1+1\] \[\frac{1}{2}f(2)+-1+4f(2)=1+1\] solve for \(f(2)\)

OpenStudy (anonymous):

\[\frac{9}{2}f(2) = 3\]\[f(2) = \frac23\]Is that right?

OpenStudy (zarkon):

yes...2/3

OpenStudy (anonymous):

Thank you so much! I think I just made an arithmetic error somewhere :/. Again, thanks!

OpenStudy (anonymous):

@Calcmathlete a sec is an hour now :D let x=1/(1-x) , x=(x-1)/x u will have: \[f(x)+2f(\frac{1}{1-x})=x\\f(\frac{1}{1-x})+2f(\frac{x-1}{x})=\frac{1}{1-x}\\f(\frac{x-1}{x})+2f(x)=\frac{x-1}{x}\] three equation with three unknowns \[f(x) \ \ \ and \ \ \ f(\frac{1}{1-x}) \ \ \ and \ \ \ f(\frac{x-1}{x}) \] solving for f(x) gives \[f(x)=\frac{1}{9}(\frac{4(x-1)}{x}+\frac{2}{x-1}+x) \]

OpenStudy (anonymous):

lol. Thanks :D

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!