👉 Learn how to evaluate the tangent of a half-angle. When given the value of the tangent of an angle, we can evaluate the tangent of half the angle using the tangent half-angle formula. When the ...

👉 Learn how to evaluate the inverse of reciprocal trigonometric functions. Recall that the reciprocal trigonometric functions are given by the ratio of 1 and the corresponding trigonometric function.

There are two versions of the cosine rule: Find an unknown side using 𝑎² = 𝑏² + 𝑐² – 2𝑏𝑐 cos𝐴 Find an unknown angle using cos𝐴 = \(\frac{𝑏² + 𝑐² – 𝑎²}{2𝑏𝑐}\) Scientific calculators need to ...