GCSE Edexcel Trigonometry - Edexcel Trigonometric graphs - Higher The three trigonometric ratios; sine, cosine and tangent are used to calculate angles and lengths in right-angled triangles. The ...

Cosine and sine of an angle θ are defined to be the x and y-coordinates of the point P on the unit circle with the property that the line from O to P makes and angle θ with the positve x-axis. cos(θ) ...

x = 30 ∘ Draw the horizontal line y = 0.5. The line y = 0.5 crosses the graph of y = sin x four times in the interval 360 ∘ ≤ θ ≤ 360 ∘ so there are four solutions.