Ist part of the expression
=3(sinx-cosx)^4=3(sinx−cosx)4
=3(sin^2x+cos^2x-2sinxcosx)^2=3(sin2x+cos2x−2sinxcosx)2
=3(1-2sinxcosx)^2=3(1−2sinxcosx)2
=3-12sinxcosx+12sin^2xcos^2x=3−12sinxcosx+12sin2xcos2x
2nd part of the expression
=6(sinx+cosx)^2=6(sinx+cosx)2
=6(sin^2x+cos^2x+2sinxcosx)=6(sin2x+cos2x+2sinxcosx)
=6+12sinxcosx=6+12sinxcosx
3rd part of the expression
=4(sin^6x+cos^6x)=4(sin6x+cos6x)
=4((sin^2x+cos^2x)^3-3sin^2xcos^2x(sin^2x+cos^2x)=4((sin2x+cos2x)3−3sin2xcos2x(sin2x+cos2x)
=4(1-3sin^2xcos^2x)=4(1−3sin2xcos2x)
=4-12sin^2xcos^2x=4−12sin2xcos2x
So whole part
= 3 -12sinxcosx+12sin^2xcos^2x
+6+12sinxcosx+4-12sin^2xcos^2x=3−12sinxcosx+12sin2xcos2x+6+12sinxcosx+4−12sin2xcos2x
=13=13