How do you find the derivative of y = cot5x + csc5x ?

1 Answer

-5csc 5x (cosec 5x-cot 5x)or -5 csc 5x × tan 5x/2

Explanation:

Given y=cot 5x+csc 5x
d/dx(cot x)=-csc^2 x
d/dx(csc x)=-csc x cot x

Now, By chain rule,
d/dx(cot 5x)=-5csc^2 5x
d/dx(csc 5x)=-5csc 5x cot 5x

Adding, we get,
-5csc 5x (cosec 5x-cot 5x) which is the answer.

Further simplifying,
csc 5x-cot 5x " as " tan (5x/2) by the identity csc x-cot x =tan (x/2)
We get the answer as-5 csc 5x × tan 5x/2