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If $f : R \rightarrow R$ be defined by $f(x) = 2x + \cos x$, then $f$ |
has a minimum at $x = \pi$ has a maximum at $x = 0$ is a decreasing function is an increasing function |
is an increasing function |
The correct answer is Option (4) → is an increasing function ## We have, $f(x) = 2x + \cos x$ $∴f'(x) = 2 + (-\sin x) = 2 - \sin x$ Since, $f'(x) > 0, \forall \ x$ Hence, $f(x)$ is an increasing function. |
