Hi, I've got this assignment: "Decide the smallest value to the function $\displaystyle f(x)= x^4/4 + x^3$. I know how to differentiate but I got a bit unsecure when the divided by four got there.
To differentiate $\displaystyle a\cdot g(x)$ where $\displaystyle a$ is a constant ($\displaystyle a = 1/4$ in this case), differentiate $\displaystyle g(x)$ and multiply the result by $\displaystyle a$. So, what do you get when you differentiate $\displaystyle f(x)$ and equate it to 0?