CUET Preparation Today
The set of value of k, for which the function $f(x)=kx^3+5$ is decreasing is : |
(0, ∞) (-∞, 0) (1, ∞) (-∞, 1) |
(-∞, 0) |
The correct answer is Option (2) → (-∞, 0) $f(x)=kx^3+5$ for $f(x)$ to be decreasing, $f'(x)<0$ $⇒k2x^2<0$ $⇒k<0⇒(-∞, 0)$ |
