Function: trigexpand (expr)

    • Expands trigonometric and hyperbolic functions of sums of angles and of multiple angles occurring in expr.

    Example:
      Trigonometric expansion
        (%i) trigexpand(sin(x+y));
        (%o) sin(x)*cos(y)+cos(x)*sin(y)

        (%i) trigexpand(cos(x+y));
        (%o) cos(x)*cos(y)-sin(x)*sin(y)

        (%i) trigexpand(tan(x+y));
        (%o) (tan(y)+tan(x))/(1-tan(x)*tan(y))

      Double-Angle Formula
        (%i) trigexpand(sin(2*x));
        (%o) 2*cos(x)*sin(x)

        (%i) trigexpand(cos(2*x));
        (%o) cos(x)^2-sin(x)^2

        (%i) trigexpand(tan(2*x));
        (%o) 2*tan(x)/(1-tan(x)^2)
    See Also:
    •  MAXIMA :: TRIGREDUCE ... Combines products and powers of trigonometric and hyperbolic

    EXAMPLE: