Number of roots of the function $f(x)=\frac{1}{(x+1)^3}-3x+\sin x$ is
Answer & explanation
Correct answer: option 3
Hence f (x) is always decreasing, also as x→∞, f (x)→−∞ and as x→−∞, f (x)→+∞
graph is as shown
as graph cuts x-axis at two distinct points two roots exist.
$=\frac{-3}{(x+1)}-3\cos x>0$