SSC GD Constable Trig Identities

Trig identities are ready-made formulas that help you convert complex trigonometric expressions into simpler forms. Think of them as shortcuts that save time in calculations

sin²θ + cos²θ = 1 2. From this: 1 + tan²θ = sec²θ and 1 + cot²θ = cosec²θ 3

- sin2θ = 2sinθcosθ - cos2θ = cos²θ - sin²θ = 2cos²θ - 1 = 1 - 2sin²θ - tan2θ = 2tanθ/(1 - tan²θ) 4

- sin(A + B) = sinAcosB + cosAsinB - sin(A - B) = sinAcosB - cosAsinB - cos(A + B) = cosAcosB - sinAsinB - cos(A - B) = cosAcosB + sinAsinB

verification of identities, simplification of expressions, finding values using identities, and proving given equations. Questions often combine multiple identities in one problem

Whenever you see sin²θ or cos²θ in an expression, immediately think of replacing them using sin²θ + cos²θ = 1. This often simplifies complex expressions instantly.