Find partial deriv's w/r and w/theta using appropriate chain rule for :
w=the square root of (25-5x^2-5y^2), where x=r cos theta, y= r sin theta.
w = (25 - 5r^2(cos^2 (theta) + sin^2(theta)))^1/2 or
w = (25 - 5r^2)^1/2 ( as (cos^2 (theta) ...
The expert finds partial derivatives for a function using the appropriate chain rule.