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Question
Let the f : R → R be defined by f (x) = 2x + cosx, then f : ______.
Options
has a minimum at x = π
has a maximum, at x = 0
is a decreasing function
is an increasing function
Solution
Let the f : R → R be defined by f (x) = 2x + cosx, then f : is an increasing function.
Explanation:
Given that f(x) = 2x + cos x
f'(x) = 2 – sin x
Since f'(x) > 0 ∀ x
So f(x) is an increasing function.
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