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Evaluate the integral of $ cos(2x) $ from $ 0 $ to $ frac{pi}{2} $

Answer 1

Abigail Nelson

Charlotte Davis

To evaluate the integral of $ \cos(2x) $ from $ 0 $ to $ \frac{\pi}{2} $:

$ \int_0^{\frac{\pi}{2}} \cos(2x) \, dx $

Use the substitution $ u = 2x $, then $ du = 2dx $ or $ dx = \frac{1}{2} du $:

$ \int_0^{\frac{\pi}{2}} \cos(2x) \, dx = \frac{1}{2} \int_0^{\pi} \cos(u) \, du $

The integral of $ \cos(u) $ is $ \sin(u) $:

$ \frac{1}{2} \left[ \sin(u) \right]_0^{\pi} $

Evaluate the definite integral:

$ \frac{1}{2} \left( \sin(\pi) – \sin(0) \right) = \frac{1}{2} (0 – 0) = 0 $

Therefore, the final answer is:

$ 0 $

Answer 2

Alex Thompson

Daniel Carter

To evaluate the integral of $ cos(2x) $ from $ 0 $ to $ frac{pi}{2} $, use the substitution $ u = 2x $:

$ int_0^{frac{pi}{2}} cos(2x) , dx = frac{1}{2} int_0^{pi} cos(u) , du $

The integral of $ cos(u) $ is $ sin(u) $:

$ frac{1}{2} left[ sin(u)
ight]_0^{pi} $

Evaluate the definite integral:

$ frac{1}{2} (0 – 0) = 0 $

Answer 3

Amelia Mitchell

Matthew Carter

To evaluate the integral of $ cos(2x) $ from $ 0 $ to $ frac{pi}{2} $, use the substitution $ u = 2x $:

$ frac{1}{2} int_0^{pi} cos(u) , du $

The result is $ 0 $