Cosine of the difference and sum of two numbers
Sine of the difference and sum of two numbers
Tangent of the difference and sum of two numbers
Few more derivations based on the above formulas
Formula to transform the product into sum or difference
Formula to transform the sum or difference into product
Value of trigonometric functions at in terms of values at
Value of trigonometric functions at in terms of values at
Value of trigonometric functions at in terms of values at
Values of trigonometrical functions at some important points
Law of Sines or Sine Rule
Law of Cosines
or
or
or
Projection Formula
Napier’s Analogy (law of tangents). In any , we have
Area of a Triangle
Solving trigonometric equations
Step 1: Find a value of , preferably between
and
or between
and
satisfying the given equation and call it
Step 2:
- If the equation is
, then
as a general solution
- If the equation is
, then
as a general solution
- If the equation is
, then
as a general solution