Understand and use the standard small angle approximations of sine, cosine and tangent: sin θ ≈ θ, cos θ ≈ 1 – θ²/2, tan θ ≈ θ where θ is in radians(Pearson Edexcel A-Level)

Mastery Mind: Mathematics Revision · Oct 20, 2026 · 5m

Small-angle approximations let you replace trigonometric functions with simple algebra when the angle is close to zero in radians. In Edexcel Topic 5.2, the formulae are provided, so the marks come from accurate substitution of the whole argument, clear algebra and a disciplined check of the angle unit. Listen to this audio revision guide for Understand and use the standard small angle approximations of sine, cosine and tangent: sin θ ≈ θ, cos θ ≈ 1 – θ²/2, tan θ ≈ θ where θ is in radians. Test your knowledge with interactive exam questions and flashcards at…