calculus
posted by Sasha .
A. find y' by implicit differentiation.
B. solve th equation explicitly for y and differentiate to get y' in terms of x.
cos (x) + √y = 5

a)
 sin(x) + (1/2)y^(1/2)dy/dx = 0
(1/4)(1/√y)dy/dx = sin(x)
dy/dx = 4√y sin(x)
b)
√y = 5  cosx
y = 25  10cosx + cos^2 x
dy/dx = 10cosx + 2(cosx)(sinx)
= 2cosx(5cos(x) + 2sin(x))