1.

prove that 3 cos^(-1) x = cos^(-1) (4x^3 - 3x), x in [1/2,1]

Answer»

Solution :PUT `COS^(-1) x = y.` Then cos y = x
`therefore 4x^3 - 3X = 4 cos^3 y - 3 cos y = cos 3y`
`IMPLIES 3y = cos^(-1) (4x^3 - 3x)`
`implies 3 cos^(-1) x = (4x^3 - 3x)`


Discussion

No Comment Found

Related InterviewSolutions