Q. The angle θ1 is located in Quadrant IV, and sin(θ1)=−8513.What is the value of cos(θ1) ? Express your answer exactly.cos(θ1)=
Apply Pythagorean identity: Use the Pythagorean identity for sine and cosine.The Pythagorean identity states that sin2(θ)+cos2(θ)=1.We know sin(θ1)=−8513, so we can find cos2(θ1) using the identity.