Question #6b0f2

1 Answer
Jan 16, 2018

See below...

Explanation:

We know,

#sin^2x+cos^2x=1#
#=>(sinx-cosx)^2+2sinxcosx=1#
#=>(1/2)^2+2sinxcosx=1#
#=>2sinxcosx=3/4#
#=>sinxcosx=3/8#

Now,
#sin^4x+cos^4x#
#=(sin^2x+cos^2x)^2-2sin^2xcos^2x#
#=1-2xx(3/8)^2#
#=1-9/32#
#=23/32#

Hope it helps...
Thank you...