Question #71dff

1 Answer
Jan 26, 2017

Ist part of the expression

=3(sinx-cosx)^4=3(sinxcosx)4

=3(sin^2x+cos^2x-2sinxcosx)^2=3(sin2x+cos2x2sinxcosx)2

=3(1-2sinxcosx)^2=3(12sinxcosx)2

=3-12sinxcosx+12sin^2xcos^2x=312sinxcosx+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)33sin2xcos2x(sin2x+cos2x)

=4(1-3sin^2xcos^2x)=4(13sin2xcos2x)

=4-12sin^2xcos^2x=412sin2xcos2x

So whole part

= 3 -12sinxcosx+12sin^2xcos^2x +6+12sinxcosx+4-12sin^2xcos^2x=312sinxcosx+12sin2xcos2x+6+12sinxcosx+412sin2xcos2x

=13=13