What is the integral from 0 to pi of 2xsin(3x) ?

The integral from 0 to pi of 2xsin(3x) is (2pi)/3

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integral from 0 to pi of 2xsin(3x)

\int_{0}^{π} 2 x sin (3 x) d x

\frac{2 π}{3}

Decimal

2.09439 \dots

Solution steps

\int_{0}^{π} 2 x sin (3 x) d x

Take the constant out:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= 2 \cdot \int_{0}^{π} x sin (3 x) d x

Apply Integration By Parts

= 2 [\frac{1}{3} (- x cos (3 x) - 3 \cdot \int - \frac{1}{3} cos (3 x) d x)]_{0}^{π}

\int - \frac{1}{3} cos (3 x) d x = - \frac{1}{9} sin (3 x)

= 2 [\frac{1}{3} (- x cos (3 x) - 3 (- \frac{1}{9} sin (3 x)))]_{0}^{π}

Simplify

2 [\frac{1}{3} (- x cos (3 x) - 3 (- \frac{1}{9} sin (3 x)))]_{0}^{π} : 2 [\frac{1}{3} (- x cos (3 x) + \frac{1}{3} sin (3 x))]_{0}^{π}

= 2 [\frac{1}{3} (- x cos (3 x) + \frac{1}{3} sin (3 x))]_{0}^{π}

Compute the boundaries:

\frac{π}{3}

= 2 \cdot \frac{π}{3}

Simplify

= \frac{2 π}{3}

What is the integral from 0 to pi of 2xsin(3x) ?
The integral from 0 to pi of 2xsin(3x) is (2pi)/3