Find the Exact Value cos(-30 degrees )

Problem

cos(−30)

Solution

1. Apply the even-odd identity for the cosine function, which states that cos(−θ)=cos(θ)

cos(−30)=cos(30)

2. Identify the value of cos(30) using the unit circle or a standard 30−60−90 reference triangle.

cos(30)=√(,3)/2

Final Answer

cos(−30)=√(,3)/2

Want more problems? Check here!