Where are the minimum and maximum values for f(x) = 2 sin x - 1 on the interval [0, 2π]?A. min:z = 0, 2 max:z =OB. min:z =max:z = 0,2플max:z = 0, 7, 2nC. min:z = max:z =D. min:z =Reset Selection

Where are the minimum and maximum values for f(x) = 2 sin x - 1 on the interval [0, 2π]?A. min:z = 0, 2 max:z =OB. min:z =max:z = 0,2플max:z = 0, 7, 2nC. min:z = class=

Answer :

Recall that the maximum/minimum value of a function is the place where a function reaches its highest/lowest point.

We know that:

[tex]\begin{gathered} For\text{ }all\text{ }x\in[0,2\pi] \\ -1\leq\sin(x)\leq1. \end{gathered}[/tex]

Multiplying the above result by 2 we get:

[tex]\begin{gathered} -1\times2\leq\sin(x)\times2\leq1\times2, \\ -2\leq2\sin(x)\leq2. \end{gathered}[/tex]

Subtracting 1 from the above inequality we get:

[tex]\begin{gathered} -2-1\leq2\sin(x)-1\leq2-1, \\ -3\leq2\sin(x)-1\leq1. \end{gathered}[/tex]

Therefore f(x) reaches a minimum at:

[tex]x=\frac{3\pi}{2}.[/tex]

And f(x) reaches a maximum at:

[tex]x=\frac{\pi}{2}.[/tex]

Answer: Option C.

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