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Evaluate 17 sin(x) cos(x) dx by four methods.

User Koro
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Final answer:

To evaluate the integral 17 sin(x) cos(x) dx by four methods, we can use integration by substitution, integration by parts, trigonometric identities, or the double angle formula. Each method involves different techniques to find the antiderivative of the given function.

Step-by-step explanation:

To evaluate the integral 17 sin(x) cos(x) dx by four methods, we can use different techniques such as integration by substitution, integration by parts, trigonometric identities, or the double angle formula.



Method 1: Integration by Substitution

Let u = sin(x), then du = cos(x) dx. Substituting these values, we have:

17 sin(x) cos(x) dx = 17 u du

Integrating, we get:

17 integral(u du) = 17(u^2/2) + C = 17/2 sin^2(x) + C



Method 2: Integration by Parts

Let u = sin(x) and dv = 17 cos(x) dx. Then, du = cos(x) dx and v = 17 sin(x). Applying the integration by parts formula:

17 sin(x) cos(x) dx = u v - integral(v du)

17 sin(x) cos(x) dx = 17 sin(x) sin(x) - integral(17 sin(x) cos(x) dx)

Simplifying and rearranging, we get:

2 integral(17 sin(x) cos(x) dx) = 17 sin^2(x)

Integrating both sides, we have:

2(17/2) integral(sin(x) cos(x) dx) = 17 integral(sin^2(x))

17 integral(sin(x) cos(x) dx) = 17/2 sin^2(x) + C



Method 3: Trigonometric Identities

Using the trigonometric identity sin(2x) = 2 sin(x) cos(x), we can rewrite the integral as:

17 sin(x) cos(x) dx = 1/2 * 17 sin(2x) dx

Integrating, we get:

1/2 * 17 integral(sin(2x) dx) = (17/4) cos(2x) + C



Method 4: Double Angle Formula

Using the double angle formula, sin(2x) = 2 sin(x) cos(x), we can rewrite the integral as:

17 sin(x) cos(x) dx = (17/2) sin(x) (1 - sin^2(x)) dx

Expanding and integrating, we get:

(17/2) integral(sin(x) - sin^3(x)) dx = (-17/2) cos(x) + (17/4) cos^3(x) + C

User Yerko Palma
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