Question

alpha + beta is equal to 90 degree then the value of cos square alpha + cos square beta is​

Answer 1

Step-by-step explanation:

$\alpha + \beta = 90 \\ \alpha =90 - \beta \\ \cos( \alpha ) = \cos(90 - \beta ) \\ \cos( \alpha ) = \sin( \beta ) \\ so \\ { \cos( \alpha ) }^{2} + { \sin( \beta ) }^{2} \\ 2 { \cos( \alpha ) }^{2} \\ or \\ 2 { \sin( \beta ) }^{2}$