What is the integral from 0 to 2pi of 9sin^2(t) ?

The integral from 0 to 2pi of 9sin^2(t) is 9pi

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integral from 0 to 2pi of 9sin^2(t)

\int_{0}^{2 π} 9 sin^{2} (t) d t

9 π

Decimal

28.27433 \dots

Solution steps

\int_{0}^{2 π} 9 sin^{2} (t) d t

Take the constant out:

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

= 9 \cdot \int_{0}^{2 π} sin^{2} (t) d t

Rewrite using trig identities

= 9 \cdot \int_{0}^{2 π} \frac{1 - cos ( 2 t )}{2} d t

Take the constant out:

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

= 9 \cdot \frac{1}{2} \cdot \int_{0}^{2 π} 1 - cos (2 t) d t

Apply the Sum Rule:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= 9 \cdot \frac{1}{2} (\int_{0}^{2 π} 1 d t - \int_{0}^{2 π} cos (2 t) d t)

\int_{0}^{2 π} 1 d t = 2 π

\int_{0}^{2 π} cos (2 t) d t = 0

= 9 \cdot \frac{1}{2} (2 π - 0)

Simplify

9 \cdot \frac{1}{2} (2 π - 0) : 9 π

= 9 π

What is the integral from 0 to 2pi of 9sin^2(t) ?
The integral from 0 to 2pi of 9sin^2(t) is 9pi