Question

If Cos A =2/3 and A+B=90°, find the value of Sin B

Answer 1

Answer:

$\cos \: a = 2 \div 3 \\ a + b = 90 \: \: \: \: \: (1) \\ a = 90 - b \\ \cos(90 - b) = 2 \div 3 \\ \ \: (sin \: b = 2 \div 3)$