Question

Prove the following: 3cos⁻¹x=cos⁻¹(4x³-3x),x⋲[1/2,1]

Answer 1

Answer:

2 I hope this is the correct answer

Answer 2

${\blue{3 {cos}^{ - 1} x = {cos}^{ - 1} (4x {}^{3} - 3x)}}</p><p>\\ let \: x = \cosθ \\ Then, \: \\ {cos}^{ - 1} = θ \\ →RHS, \\ {cos}^{ - 1} (4x {}^{3} - 3x) \\ = {cos}^{ - 1} (4 {sin}^{3} θ - 3cosθ) \\ = cos {}^{ - 1} (cos \: 3θ) \\ = 3θ\\ = 3cos {}^{ - 1} x = LHS$

_____________________Proved!!!