y = √(cos(x))
1
Rewrite square root as power:
y = (cos(x))^(1/2)
2
Identify inner and outer functions:
Outer: f(u) = u^(1/2), Inner: g(x) = cos(x)
3
Differentiate outer function (power rule):
f'(u) = (1/2)u^(-1/2) = 1/(2√u)
4
Differentiate inner function:
g'(x) = -sin(x)
5
Apply chain rule:
y' = (1/(2√(cos(x)))) · (-sin(x))
6
Simplify:
y' = -sin(x)/(2√(cos(x)))
y' = -sin(x)/(2√(cos(x)))