Science:Math Exam Resources/Courses/MATH110/December 2013/Question 06 (c)/Hint 1

The derivative was computed in part (b):

$\displaystyle f'(x)=\left(3x^{2}+4x+1\right)\cdot e^{x^{3}+2x^{2}+x-3}.$

Now set the derivative and solve. This can be done either by factoring or using the quadratic formula.