(Q1)For which value of acute angle
(i)

cosθ

1-sinθ

+

cosθ

1+sinθ

=4 is true? For which value of 0° ≤ θ ≤ 90°,above equation is not defined?

Answer:

Given

cosθ

1-sinθ

+

cosθ

1+sinθ

=4

cosθ(1+sinθ)+cosθ(1-sinθ)

(1-sinθ)(1+sinθ)

=

4

1

cosθ+cosθ.sinθ+cosθ-cosθ.sinθ

1-sin²θ

=

4

1

2cosθ

cos²θ

=

4

1

2

cosθ

=

4

1

[by cross multiplication]

cosθ=

cosθ=cos °

θ=°

Is given statement is