#Tan^2x-sin^2x #
#=> sin^2x/cos^2x-sin^2x # #color(white)(wwwwwwwww# #["as " tanx = sinx/cosx]#
#=> (sin^2x - sin^2xcos^2x)/cos^2x#
#=> (sin^2x(1 - cos^2x))/cos^2x# #color(white)(wwwwww# #["as " sin^2x + cos^2x =1]#
#=> (sin^2x(sin^2x))/cos^2x#
#=>tan^2xsin^2x#