Exact value
Find the exact value by using a sum or difference identity. Which is the correct answer?
cos 20 cos 25 - sin 20 sin 25 (angles are in degrees)
1
-√2/2
√2/2
√3/2
https://brainmass.com/math/basic-calculus/exact-value-difference-identities-29182
Solution Summary
This shows how to find the exact value by using a sum or difference identity.
$2.49