Question

tanx1tanx2=p then cos(x1-x2)/cos(x1+x2)​

Answer 1

l

ANSWER

cos(θ

1

+θ

2

)

cos(θ

1

−θ

2

)

=

cosθ

1

cosθ

2

−sinθ

1

sinθ

2

cosθ

1

cosθ

2

+sinθ

1

sinθ

2

Divide numerator and denomenator by cosθ

1

cosθ

2

=

1−tanθ

1

tanθ

2

1+tanθ

1

tanθ

2

=

1−kcotθ

2

tanθ

2

1+kcotθ

2

tanθ

2

=

1−k

1+k