Ratios of Compound angles

  • Compound angles are formed by adding, subtracting, multiplying, or dividing two or more angles.
  • The trigonometric functions of a sum or difference of two angles can be expressed in terms of the trigonometric functions of the individual angles.
  • The sum and difference formulas for sine and cosine are commonly used to simplify trigonometric expressions.
  • The product-to-sum and sum-to-product identities can be used to simplify expressions involving products or powers of trigonometric functions.
  • The half-angle formulas can be used to find the values of trigonometric functions for angles that are half the size of known angles.


Important Formulas to Remember in these Ratios of Compound angles

  • \( \sin(A\pm B)=\sin A\cos B\pm\cos A\sin B \)
  • \( \cos(A\pm B)=\cos A\cos B\mp\sin A\sin B \)
  • \( \tan(A\pm B)=\frac{\tan A\pm\tan B}{1\mp\tan A\tan B} \)