How do you simplify #secxtan^2x+secx#?

1 Answer
Jul 15, 2016

#sec x tan^2 x + sec x = sec^3 x#

Explanation:

For this problem, we can use the identity

#sec^2 x - 1 = tan^2 x#

Rewriting our expression yields

#sec x tan^2 x + sec x = sec x(sec^2 x - 1) + sec x#

#= sec^3 x cancel(- sec x + sec x)#

#= sec^3 x#

We can check our answer by graphing both of them, for example.

Graph of #sec x tan^2 x + sec x #
graph{sec x * tan x * tan x + sec x [-28.87, 28.86, -14.43, 14.44]}
Graph of #sec^3 x#
graph{sec x * sec x * sec x [-28.87, 28.86, -14.43, 14.44]}