The integral is .

Rewrite the integral as .

Consider .

Here the integrand function is an odd function.

From the symmetric property of the integrals, .

Consider .

Determine the integral interms of an area.

Find the area of the region under the curve using graphing utility.

Graphically the area of the region under the curve is .

.

Required integral is three times the area of the semicircle.

Therefore, .

Substitute results of and in .

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