The function $f(x)=2x^3+3x^2-12x+1$ is strictly increasing in :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $(-∞, -2) ∪ (1, ∞)$
$f(x)=2x^3+3x^2-12x+1$
$f'(x)=6x^2+6x-12=0$
$6(x+2)(x-1)=0$, $x=1,-2$
Using wavy curve
f(x) strictly increasing in $(-∞, -2)∪(1, ∞)$