A function is matched below against an interval where it is supposed to be increasing. Which of the following parts is incorrectly matched? Interval, Function [2, `oo)` , `2x^3-3x^2-12 x+6` `(-oo,oo)` , `x^3=3x^2+3x+3` `(-oo-4)` , `x^3+6x^2+6` `(-oo,1/3)` , `3x^2-2x+1`

Options

A. `[2,oo),2x^(3)-3x^(2)-12x+6`
B. `[-oo,oo),x^(3)-3x^(2)-3x+3`
C. `[-oo,-4),x^(3)-6x^(2)+6`
D. `[-oo,(1)/(3)],3x^(2)-2x+1`

Answer

4

Explanation

f(x)=`3x^(2)-2x+1`
`therefore f(X)=6x-2`
f is increasing .Thus `f(x)ge0i.e`
`6x-2ge or x ge1/3`