For the function f(x,y)=excos(y), what is the value of ∂^2f/∂x∂y at (x=0, y=π/2)?

For the function f(x)=x4-x2, which of the following statements is/are TRUE?

A function y(x) is defined in the interval on the x-axis as Which one of the following is the area under the curve for the interval on the x-axis?