posted by mikki on .
find the critical points , increasing & decreasing interval and concavity.Please just show me the steps on how to get the increasing and decreasing interval and critical pts . Thanks :)
Just use your derivatives.
f = x^2 lnx
f' = 2x*lnx + x^2 * 1/x = x(2lnx + 1)
f' = 2lnx + 2x*1/x + 1 = 2lnx + 3
Now, f is increasing when f' > 0
f is concave up when f'' > 0
max/min is where f' = 0 and f'' =/= 0
inflection where f'' = 0
Go for it!