Question

prove that sec^4+2sin^2.cos^2+cos^4= 1

Answer 1

Answer:

hey mate !! here is your answer...

Step-by-step explanation:

RHS=2(cos

4

x+sin

4

x)

=2((cos

2

x)

2

+(sin

2

x)

2

)

=2((cos

2

x+sin

2

x)−2sin

2

xcos

2

x)

=2−4sin

2

xcos

2

x

=2−4.

2

1−cos2x

×

2

1+cos2x

=2−(1−cos

2

2x)=1+cos

2

2x