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The function f:R rarr R be defined by f(...

The function `f:R rarr R` be defined by `f(x)=2x+cosx` then `f`

A

has minimum at x=`pi`

B

has a maximum at x=0

C

is a decreasing function

D

is in increasing function

Text Solution

Verified by Experts

The correct Answer is:
D
We have, `f(x)=2x + cosx`
`therefore f^(')(x)=2 + (-sinx)=2-sinx`
Since, `f^(')(x)gt0, (AA)x`
Hence, f(x) is an increasing function.
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