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

Key Questions

  • What is Derivatives of #y=sec(x)# ?

    #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)#

    Sally · 3 · Sep 7 2014

Questions

Differentiating Trigonometric Functions