6. Trigonometric Identities and More Equations

In Exercises 55–58, use the given information to find the exact value of each of the following:

b. cos(α/2)

sec α = ﹣3, 𝝅/2 < α < 𝝅

In Exercises 55–58, use the given information to find the exact value of each of the following:

c. tan(α/2)

sec α = ﹣3, 𝝅/2 < α < 𝝅

In Exercises 59–68, verify each identity.

cos²(θ/2) = (sec θ + 1)/(2 sec θ)