Question #3d5bd
1 Answer
Apr 4, 2017
#tanx+cosx/(1+sinx)=1/cosx#
Manipulate just the left-hand side.
#tanx+cosx/(1+sinx)=sinx/cosx+cosx/(1+sinx)#
Common denominator:
#=(sinx(1+sinx))/(cosx(1+sinx))+(cosx(cosx))/(cosx(1+sinx))#
#=(sinx+sin^2x+cos^2x)/((cosx)(1+sinx))#
Recall that
#=(sinx+1)/(cosx(1+sinx))#
#=1/cosx#
Thus the identity is proven.
