math, Calculus
posted by Reisha .
Find the relative extrema of the functions.
f(x)=4x/(x^2+1)
f(x)=1/(x2)
take the derivative, set to zero.
the first as an example:
f(x)= 4x (x^2 +1)^1
f'(x)= 4 (x^2 +1)^1 4x(2x)(x^2 +1)^2
set to zero. Multiply through by (x^2+1)^2
0=4(x^2+1)  8x^2
4x^2=1
x= + 1/2
what about the second question
f(x)1/(x2)
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