Prove that

Question:

If $\tan \theta=\sqrt{3}$ then $\sec \theta=$ ?

(a) 2

(b) $\frac{1}{2}$

(c) $\frac{\sqrt{3}}{2}$

(d) $\frac{2}{\sqrt{3}}$

 

Solution:

Given : $\tan \theta=\frac{\sqrt{3}}{1}$

Since, $\tan \theta=\frac{P}{B}$

$\Rightarrow P=\sqrt{3}$ and $B=1$

Using Pythagoras theorem,

$P^{2}+B^{2}=H^{2}$

$\Rightarrow(\sqrt{3})^{2}+1^{2}=H^{2}$

$\Rightarrow H^{2}=3+1$

$\Rightarrow H^{2}=4$

$\Rightarrow H=2$

Therefore,

$\sec \theta=\frac{H}{B}=\frac{2}{1}=2$

Hence, the correct option is (a).

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