Question

If cos B=21/29 find the value of sin B given that angle B is in the first quadrant

Answer 1

G.T cosB = 21/29

w.k.t
$\sin(x) = \sqrt{1 - { \cos(x) }^{2} }$
therefore,
sinB =
$\sqrt{1 - ( \frac{21}{29} )^{2} }$
= 20/29