JEE Main 2017 · 9 Apr · Shift 1 · Mathematics Q72

MathematicsSingle correct+4 / -1Question 72 of 90

The function $f$ defined by $f(x)=x^3-3x^2+5x+7$ , is :

increasing in

\mathbb R

decreasing in

\mathbb R

decreasing in

(0,\infty)

and increasing in

(-\infty,0)

increasing in

(0,\infty)

and decreasing in

(-\infty,0)

Answer and worked solution

Official answer: A

$f'(x)=3x^2-6x+5=3(x-1)^2+2>0$ , so $f$ is increasing on $\mathbb R$ .

JEE Main 2017 · 9 Apr · Shift 1, Mathematics question 72