Trigonometric Identities Reference Sheet, Cheat Sheet of Trigonometry

Download Trigonometric Identities Reference Sheet and more Cheat Sheet Trigonometry in PDF only on Docsity! Trigonometric Identities Reference Sheet Reciprocal Identities • sin θ = 1 csc θ • csc θ = 1 sin θ • cos θ = 1 sec θ • sec θ = 1 cos θ • tan θ = 1 cot θ • cot θ = 1 tan θ Quotient Identities • tan θ = sin θ cos θ • cot θ = cos θ sin θ Pythagorean Identities • sin2 θ + cos2 θ = 1 • tan2 θ + 1 = sec2 θ (This is just sin2 θ + cos2 θ = 1 divided through by cos2 θ) • 1 + cot2 θ = csc2 θ (This is just sin2 θ + cos2 θ = 1 divided through by sin2 θ) Sum & Difference Formulas • sin (α± β) = sinα cos β ± cosα sin β (This is two formulas) • cos (α± β) = cosα cos β ∓ sinα sin β (This is two formulas; note the change in signs!) 1