Function `f(x)=2x^3-9x^2+12 x+29` is monotonically decreasing when (a) `x<2` (b) `x >2` (c) `x >3` (d) `1

Explanation

`f(x)=2 x^{3}-9 x^{2}+12 x+29 `
`
f^{prime}(x)=6 x^{2}-18 x+12 `
`
=6(x^{2}-3 x+2) `
`
=6(x-1)(x-2) `


For f(x) to be decreasing, we must have
`

f^{prime}(x)<0 `
`
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