7. Non-Right Triangles

In Exercises 57–64, find the exact value of the following under the given conditions:a. cos (α + β)3 3𝝅 1 3𝝅 tan α = ------ , 𝝅 < α < -------- , and cos β = ------- , ---------- < β < 2𝝅.4 2 4 2

In Exercises 69–74, rewrite each expression as a simplified expression containing one term.cos (α + β) cos β + sin (α + β) sin β