Question #e94cc
1 Answer
Jan 7, 2018
Explanation:
#"using the "color(blue)"trigonometric identities"#
#•color(white)(x)tanx=sinx/cosx#
#•color(white)(x)sin^2x+cos^2x=1#
#"consider the left hand side"#
#sinxtanx+cosx#
#=sinx xxsinx/cosx+cosx#
#=(sin^2x)/cosx+cos^2x/cosx#
#=(sin^2x+cos^2x)/cosx#
#=1/cosx=" right hand side "rArr" proven"#
#"consider the left side of the second one"#
#rArrcos^2x/sinx#
#=(1-sin^2x)/sinx#
#=1/sinx-sin^2x/sinx#
#=1/sinx-sinx=" right side "rArr"proven"#