\(sin3x = 3sinx - 4sin^3x\)
\(cos3x = 4cos^3x - 3cosx\)
\(cos^3x = \dfrac{3cosx + cos3x} {4}\)
\(sin^3x = \dfrac{3sinx - sin3x} {4}\)
\(tan3x = \dfrac{3tanx - tan^3x} {1 - 3tan^2x}\)
\(cot3\alpha= \dfrac{cot^3\alpha-3cot\alpha}{3cot^2\alpha-1}\)
Copyright © 2021 HOCTAPSGK