Question

prove that tan x = 4 tanx ( 1-tan²x ) / 1-6tan²x + tan ⁴
​

Answer 1

Answer:

ANSWER

LHS :

tan4x=tan[2(2x)]

=

1−tan

2

2x

2tan2x

=

1−(

1−tan

2

x

2tanx

)

2

2(

1−tan

2

x

2tanx

)

=

(1−tan

2

x)

2

−4tan

2

x

4tanx(1−tan

2

x)

=

1−6tan

2

x+tan

4

x

4tanx(1−tan

2

x)

= RHS