Learn how to solve for the lengths of the sides and the measures of the angles of a triangle using the law of cosines. The law of cosines is used in determining the lengths of the sides or the ...

👉 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 ...

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 ...

Detailed explanations of when and how to apply each rule Step-by-step worked examples to build understanding Practice questions with fully worked solutions to check your progress Perfect for Year ...