Question

if sina=3/4 find the value of cosa

Answer 1

sin²a + cos²a = 1
therefore,
cos²a= 1- sin²a
= 1 - 9/16
= (16-9)/16
= 7/16
therefore, cos a= √7/4

Answer 2

sinA=p/h
sinA=3/4
P=3
H=4
pythagoras th.
B²=H²-P²
B²=4²-3²
B²=16-9
B²=7
B=√7

cosA=B/H
cosA=√7/4

I hope it helps u
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