A-Level Maths Edexcel (9MA0)

Understand and use the standard small angle approximations of sine, cosine and tangent

• $\sin{θ}≈θ$,
• $\cos{θ}≈1-\dfrac{θ^2}{2}$,
• $\tan{θ}≈θ$

Where θ is in radians.

Students should be able to approximate,

e.g. $\dfrac{\cos{3x}-1}{x\sin{4x}}$ when $x$ is small, to $-\dfrac{9}{8}$.