# Math Help - Critical Points and Absolute Extrema

1. ## Critical Points and Absolute Extrema

2. $f(x) = ax^3 + bx$

$f'(x) = 3ax^2 + b$

$f''(x) = 6ax$

$\kappa(x) = \frac{6ax}{\left[1 + (3ax^2 + b)^2\right]^{\frac{3}{2}}}$

the grunt work I leave to you ... find $\kappa'(x)$ and find the critical values.