Question

find theta if sin (theta +56)=cis theta where theta and (theta +56) are less than 90degree
​

Answer 1

Step-by-step explanation:

$\sin( \alpha + 56) = \cos(?)$

$\sin( \alpha + 56) = \sin(90 - \alpha )$

$compare \: both \: the \: side$

$\alpha + 56 = 90 - \alpha$

$\alpha + \alpha = 90 - 56$

$2 \alpha = 44$

$\alpha = 22$

$\alpha \: is \: theta$