The interval in which where the function $f(x)=x^3-3x^2+4x+1, x\in R$ is increasing, is :
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → R
$f(x)=x^3-3x^2+4x+1$
$f'(x)=3x^2-6x+4=0$
$⇒3(x-1)^2+1>0$ always
so f(x) is increasing on R