# StudySquare

# Cosine for AQA A-level Maths

This page covers the following topics:

1. Cosine

2. Values and applications

3. Right-angled traingles

4. Cosine graphs and transformations

Cosine of an angle is a ratio between the side adjacent to the angle and the hypotenuse of a triangle.

Cosine is one of three trigonometric functions of an angle.

cos(x) is found by calculating the ratio of two sides of a right-angled triangle, the adjacent and the hypotenuse.

The diagram shows a cosine graph.

# 1

Find a if cosB = 0.9 and c = 40.

36

# 2

Find the value of A in the triangle shown.

46.2º

# 3

Find a if cosB = 0.3 and c = 20 cm.

6 cm

# 4

Find the length of the line p in the triangle shown.

7.4

# 5

Write down the coordinates of point B on the cosine graph.

(270º, 0)

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