Question

Prove that: 2 sec2 x - sec4x-2 cosec2 x + cosec4 x =I -tan8÷4tanx ​

Answer 1

Left side:

1

sin

4

x

−

cos

4

x

sin

4

x

=

1

−

cos

4

x

sin

4

x

=

=

(

1

−

cos

2

x

)

(

1

+

cos

2

x

)

sin

4

x

=

(

sin

2

x

)

(

1

+

cos

2

x

)

sin

4

x

=

1

+

cos

2

x

sin

2

x

=

1

sin

2

x

+

cos

2

x

sin

2

x

=

=

csc

2

x

+

cot

2

x