Question

if secx+sec2x=1then value of tan8x-tan4x-2tan2x+1 Will be equal to​

Answer 1

secx+sec

2

x=1

⇒secx=1−sec

2

x=tan

2

x

⇒sec

2

x=tan

4

x

⇒1+tan

2

x=tan

4

x

(1+tan

2

x)

2

=(tan

4

x)

2

1+tan

4

x+2tan

2

x=tan

8

x

∴tan

8

x−tan

4

x−2tan

2

x+1

=1+tan

4

x+2tan

2

x−tan

4

x−2tan

2

x+1

=2