The derivative of cosec x is

A.
tan x cosec x 
B.
cot x cosec x 
C.
tan x sec x 
D.
cot x sec x
Correct Answer: Option B
Explanation
(csc x = frac{1}{sin x})
Using the quotient rule,
(frac{mathrm d y}{mathrm d x} = frac{vdu – udv}{v^{2}})
= (frac{sin x (0) – 1 (cos x)}{(sin x)^{2}})
= (frac{ cos x}{sin^{2} x})
= ((frac{ cos x}{sin x}) (frac{1}{sin x}))
= ( cot x csc x)