Question

If cos theter=1\√5 find tan thether and sin thether

Answer 1

$cos \theta = \frac{1}{ \sqrt{5} } \\ \\ sin \theta = \sqrt{1 - {cos}^{2} \theta} \\ = \sqrt{1 - \frac{1}{5} } \\ = \frac{2}{ \sqrt{5} } \\ \\ tan \theta = \frac{sin \theta}{cos \theta} = \frac{ \frac{2}{ \sqrt{5} } }{ \frac{1}{ \sqrt{5} } } = 2$