Question

sin²theta+3cos²theta=2​

Answer 1

Step-by-step explanation:

${ \sin }^{2} ({ \theta}) + 3{ \cos }^{2} ({ \theta}) = 2 \\ \\ we \: know \: \implies \\ \\ { \sin }^{2} ({ \theta}) + { \cos }^{2} ({ \theta}) = 1 \\ \\ { \sin }^{2} ({ \theta}) + 2{ \cos }^{2} ({ \theta}) + { \cos }^{2} ({ \theta}) = 2 \\ \\ 2{ \cos }^{2} ({ \theta}) = 1 \\ \\ { \cos }^{2} ({ \theta}) = \frac{1}{2} \\ \\ \cos( \theta) = \frac{1}{ \sqrt{2} } = \cos( 45 \degree) = \sin( 45 \degree) \\ \\ \theta = 45$