Problem

Integrate Using u-Substitution integral of (sin( square root of x))/( square root of x) with respect to x

The question asks for the evaluation of an integral using the u-substitution method. The integral to be evaluated is the integral of the function (sin(√x))/(√x) with respect to x. The integral involves a trigonometric function (sine) and a square root function in its integrand.

The u-substitution method is a common technique used in calculus to simplify integration by substituting a part of the integrand with a new variable, often denoted as 'u'. This often simplifies the integral into a form that is easier to integrate. Once the integration is done in terms of 'u', the variable is then substituted back into terms of 'x' to obtain the final result. The question expects the explanation or execution of this process for the given integrand.

sin(x)xdx

Answer

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Solution:

Step:1

Implement exponent rules.

Step:1.1

Express x as x12 using the rule axn=axn.
sin(x12)xdx

Step:1.2

Again, express x as x12.
sin(x12)x12dx

Step:1.3

Transform x12 in the denominator to the numerator by using the negative exponent.
sin(x12)(x12)1dx

Step:1.4

Apply exponent multiplication in (x12)1.

Step:1.4.1

Utilize the exponent multiplication rule, (am)n=amn.
sin(x12)x121dx

Step:1.4.2

Combine the exponents 12 and 1.
sin(x12)x12dx

Step:1.4.3

Place the negative sign in front of the fraction.
sin(x12)x12dx

Step:2

Set u=x12. Then du=12x12dx, and dx=2x12du. Substitute u and du into the integral.

Step:2.1

Define u=x12 and calculate dudx.

Step:2.1.1

Differentiate x12.
ddx[x12]

Step:2.1.2

Apply the Power Rule, ddx[xn]=nxn1, where n=12.
12x121

Step:2.1.3

Express 1 as a fraction with a common denominator by multiplying by 22.
12x12122

Step:2.1.4

Combine 1 and 22.
12x1222

Step:2.1.5

Add the numerators over the common denominator.
12x122

Step:2.1.6

Simplify the numerator.

Step:2.1.6.1

Multiply 1 by 2.
12x12

Step:2.1.6.2

Subtract 2 from 1.
12x12

Step:2.1.7

Move the negative in front of the fraction.
12x12

Step:2.1.8

Simplify further.

Step:2.1.8.1

Apply the negative exponent rule bn=1bn.
121x12

Step:2.1.8.2

Multiply 12 by 1x12.
12x12

Step:2.2

Reformulate the integral with u and du.
2sin(u)du

Step:3

Extract the constant 2 from the integral as it is not dependent on u.
2sin(u)du

Step:4

Integrate sin(u) with respect to u to get cos(u).
2(cos(u)+C)

Step:5

Simplify the expression.

Step:5.1

Simplify the result.
2(cos(u))+C

Step:5.2

Multiply 1 by 2.
2cos(u)+C

Step:6

Substitute u back with x12.
2cos(x12)+C

Knowledge Notes:

  1. Exponent Rules: These include the power of a power rule, product of powers rule, and negative exponent rule, which are fundamental in simplifying expressions with exponents.

  2. u-Substitution: A technique used in integration to simplify the integral by substituting part of the integrand with a new variable, u. This often simplifies the integral into a more recognizable form.

  3. Power Rule for Differentiation: A basic rule of differentiation that states if f(x)=xn, then f(x)=nxn1.

  4. Integration of Trigonometric Functions: The integral of sin(x) is cos(x), and this is a basic integral that is often memorized.

  5. Negative Exponent Rule: States that an=1an, which is used to transform expressions with negative exponents into fractions.

  6. Constant Multiple Rule in Integration: Allows a constant to be moved outside of an integral, which can simplify the integration process.

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