What is the derivative of -csc(x)?

1 Answer
Dec 20, 2014

d/dx (-csc(x)) = -d/dx(csc(x))
Cosecant is the reciprocal of the sine function, so:
-d/dx(1/sin(x))
You should know that the derivative of 1/x = -1/x^2.
So by the chain rule: 1/f(x) = -1/f(x)^2*d/dxf(x)

Applying this here:
-(-1/(sin^2(x))*d/dxsin(x))
= -(-1/(sin^2(x))*cos(x))
= cos(x)/(sin^2(x))d
This is already an answer but in most textbooks, you see it in a different form:

1/sin(x) * cos(x)/sin(x)
= csc(x)*cot(x)

I hope this helped you in any way.