Question

1. In a right angle triangle PQR ∠Q=90⁰ and ∠R=θ and if sinθ= 5/13 then cos θ equals to​

Answer 1

In triangle PQR, ∠Q=90 and ∠R=θ.

given: sinθ= 5/13

by using identities,

sin²θ+cos²θ=1

(5/13)²+cos²θ=1

25/169+cos²θ=1

cos²θ=1-25/169

cos²θ=169-25

169

cos²θ=144

169

taking square root on both sides,

cos θ=12

13