The value of ' \(k\) ' for which the function \(f(x)=k(x+\sin x)+k\) is increasing, is equal to
The value of ' \(k\) ' for which the function \(f(x)=k(x+\sin x)+k\) is increasing, is equal to
- \(k < 0\)
- \(k>0\)
- \(k=0\)
- Data Insufficient
Solution
Given function \(f(x)=k(x+\sin x)+k\)
So, \(\quad f^{\prime}(x)=k(1+\cos x)\)
\(\because f(x)\) is an increasing function, so
\(\begin{aligned}
& f^{\prime}(x) \geq 0 \\
& \Rightarrow \quad k(1+\cos x) \geq 0 \\
& \Rightarrow \quad k > 0 \quad\{\because 1+\cos x \geq 0\} \\
\end{aligned}\)
Asked in: AP EAMCET 2020 (18 Sep Shift 1)
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