To find stationery points I always differentiate the function which in my previouas work has always resulted in a quadratic equation so set to zero and factorise or find roots.
But what to do if gradient is eg x^-2 ???
the function is 4x^2 + 1/x
dy/dx = 8x - x^-2
8x - x^-2 = 0 ??? How do I solve this?