Additional Trigonometry

Additional Trigonometry

1. Angle Rules

   • Double Angle Rules
     • sin 2A
       • 2sin A cos A
     • cos 2A
       • cos^2 A - sin^2 A
       • 1 - 2sin^2 A
       • 2cos^2 A - 1
     • tan 2A
       • (2tan A)/(1- tan^2 A)
   • Addition Formula
     • sin (A 土 B)
       • (sin A cos A) 土 (cos A sin B)
     • cos (A 土 B)
       • (cos A cos B) 干 (sin A sin B)
     • tan (A 土 B)
       • (tan A 土 tan B)/(1 干 tan A tan B)
   • R-formula
     • a sin x + b sin x = c
     • R = (a^2 + b^2)
       • R sin (x + y) = c
     • y = b/a

2. Trigo Identities

   • sin^2 x + cos^2 x = 1
   • 1 + tan^2 x = sec^2 x
   • 1 + cot^2 x = cosec^2 x
   • cosec x = 1/sin x
   • cot x = 1/tan x
   • sec x = 1/cos x
   • tan^2 x = (sin x)/(cos x)