Question

please help me in solving this question.

Answer 1

We know,

sec²x = 1+tan²x

sec x = 1/cos x

so, cos x=1/√{1+tan²x}

Answer 2

We know that sec^2 theta = 1 + tan^2 theta

$cos^2 theta = \frac{1}{sec^2 theta}$

                           = $\frac{1}{1 + tan^2 theta}$

$cos theta = \frac{1}{ \sqrt{1 + tan^2 theta} }$


Hope this helps!