- #1

Math10

- 301

- 0

## Homework Statement

Find the partial derivative of a*cos(xy)-y*sin(xy) with respect to y.

## Homework Equations

None.

## The Attempt at a Solution

The answer is -ax*sin(xy)-sin(xy)-xy*cos(xy).

I know that I need to treat x as constant since I need to take the partial derivative with respect to y. But I don't know how to get -sin(xy). I know how to get -ax*sin(xy) and -xy*cos(xy).