Derivatives of y=sec(x), y=cot(x), y= csc(x)
Key Questions

#d/dx sec(x)=sec(x)tan(x)# You could memorize this, but you can work it out too by knowing some trig properties.
The trig properties we will use are:
#sec (x)= 1/cos(x)#
and#sin x/cos x=tan x# Deriving:
#d/dx sec (x) = d/dx 1/cos(x) = (cos (x)(0)  1 (sin (x)))/( cos (x)cos (x))# (using the quotient rule)
#= sin (x)/ (cos (x) cos (x)) = sin(x)/cos(x) *(1/cos( x)) = tan (x) sec( x)=sec (x) tan (x)#
Questions
Differentiating Trigonometric Functions

Limits Involving Trigonometric Functions

Intuitive Approach to the derivative of y=sin(x)

Derivative Rules for y=cos(x) and y=tan(x)

Differentiating sin(x) from First Principles

Special Limits Involving sin(x), x, and tan(x)

Graphical Relationship Between sin(x), x, and tan(x), using Radian Measure

Derivatives of y=sec(x), y=cot(x), y= csc(x)

Differentiating Inverse Trigonometric Functions