The right triangle method converts between inverse trig functions. If sin^(-1)(x) = theta, draw a right triangle with opposite = x, hypotenuse = 1, adjacent = sqrt(1-x^2). Then: cos(theta) = sqrt(1-x^2), tan(theta) = x/sqrt(1-x^2), etc. So sin^(-1)(x) = tan^(-1)(x/sqrt(1-x^2)) = cos^(-1)(sqrt(1-x^2)) for x in [0, 1]. For negative x, use parity: sin^(-1)(-x) = -sin^(-1)(x) then convert the positive part. Similarly, if tan^(-1)(x) = theta: sin(theta) = x/sqrt(1+x^2), cos(theta) = 1/sqrt(1+x^2). These conversions are essential when different inverse trig functions appear in the same equation.