Here's the question you clicked on:
littmo12
Find a rational function f:R--> with range f(R)=[-1,1]. (Thus f(x)=P(x)/Q(x) for all xeR for suitable polynomials P and Q where Q has no real root.
could you explain it please? thankyou!
you could try something like \[f(x)=\frac{x}{x^2+1}\]
i mean to say something "like" it. that one doesn't work because the range of \[f(x)=\frac{x}{x^2+1}\] is \([-\frac{1}{2},\frac{1}{2}]\) you will have to adjust it
the first response isn't a rational function. They have to be polynomials.
only problem with @mahmit answer is \(|x+2|\) is not a polynomial
oh what @scarydoor said
@satellite73 's hint is on the money... easy to convert that to the right function.
@scarydoor how can i convert it to the right function? i dont understand
\[f(x)=\frac{ x+1 }{ x^2+1 }\] can anyone confirm this answer? i think its right...
Satellite's function is almost right, in that the range is [-1/2, 1/2]. But you want it [-1,1]. So you want to stretch it out to that. If you multiply the function by 2, then if you think about it a bit, you'll see that the range will be [-1,1].
ahh thankyou! yes it makes sense