Question

how the heck do you find the first and second partial derivatives of f(x,y) = cos(x-y) - 2sin(2x+y) .... ? x.x

Answer 1

Find first partial derivatives, then find seconds... this is an easy problem, partial differentiation is linear and you can use the chain rule.

Answer 2

would the answers look something like..cos(x-y) +4sin(2x +y) or something??

Answer 3

@missylulu partial derivative with respect to *which* variable? \(f_x=-\sin(x-y)-4\cos(2x+t)\)