Write the Function in the Form Y = F(u) and U

Multiple Choice

Write the function in the form y = f(u) and u = g(x) . Then find dy/dx as a function of x.
- $$y = \csc ( \cot x )$$

A) $y = \cot u ; u = \csc x ; \frac { d y } { d x } = \csc ^ { 2 } ( \csc x ) \csc x \cot x$
B) $y = \csc u ; u = \cot x ; \frac { d y } { d x } = \csc ^ { 3 } x \cot x$
C) $y = \csc u ; u = \cot x ; \frac { d y } { d x } = - \csc ( \cot x ) \cot ( \cot x )$
D) $y = \csc u ; u = \cot x ; \frac { d y } { d x } = \csc ( \cot x ) \cot ( \cot x ) \csc ^ { 2 } x$