How do you simplify sin4(x)cos4(x)sin2(x)+cos2(x) ?

1 Answer
Oct 21, 2016

sin4(x)cos4(x)sin2x+cos2(x)=0

Explanation:

Use:

a2b2=(ab)(a+b)

sin2(x)+cos2(x)=1

as follows:

sin4(x)cos4(x)sin2(x)+cos2(x)

=(sin4(x)cos4(x))(sin2(x)cos2(x))

=(sin2(x)cos2(x))(sin2(x)+cos2(x))(sin2(x)cos2(x))

=(sin2(x)cos2(x))(sin2(x)+cos2(x)1)

=(sin2(x)cos2(x))(11)

=0