Problem

Find dy/dx y=x^(sin(x))

The problem presented is a calculus question involving differentiation. Specifically, it asks for the derivative of the function y with respect to x, where y is defined as x raised to the power of the sine of x, or x^(sin(x)). The task involves applying rules of differentiation to find the rate of change of y with respect to x (denoted as dy/dx) for this particular function that combines both algebraic and trigonometric elements.

y=xsin(x)

Answer

Expert–verified

Solution:

Step 1:

Take the derivative of both sides with respect to x: ddx(y)=ddx(xsin(x))

Step 2:

The derivative of y with respect to x is dydx.

Step 3:

Proceed to differentiate the right-hand side.

Step 3.1:

Utilize logarithmic properties to facilitate differentiation.

Step 3.1.1:

Express xsin(x) as eln(xsin(x)): ddx[eln(xsin(x))]

Step 3.1.2:

Transform ln(xsin(x)) by bringing sin(x) in front of the log: ddx[esin(x)ln(x)]

Step 3.2:

Apply the chain rule, which states that the derivative of f(g(x)) is f(g(x))g(x), where f(x)=ex and g(x)=sin(x)ln(x).

Step 3.2.1:

Introduce u=sin(x)ln(x) to apply the chain rule: ddu[eu]ddx[sin(x)ln(x)]

Step 3.2.2:

Differentiate using the exponential rule, which says the derivative of au is auln(a) where a=e: euddx[sin(x)ln(x)]

Step 3.2.3:

Substitute u back with sin(x)ln(x): esin(x)ln(x)ddx[sin(x)ln(x)]

Step 3.3:

Apply the product rule, which says the derivative of f(x)g(x) is f(x)g(x)+g(x)f(x), where f(x)=sin(x) and g(x)=ln(x): esin(x)ln(x)(sin(x)ddx[ln(x)]+ln(x)ddx[sin(x)])

Step 3.4:

The derivative of ln(x) with respect to x is 1x: esin(x)ln(x)(sin(x)1x+ln(x)ddx[sin(x)])

Step 3.5:

Combine sin(x) and 1x: esin(x)ln(x)(sin(x)x+ln(x)ddx[sin(x)])

Step 3.6:

The derivative of sin(x) with respect to x is cos(x): esin(x)ln(x)(sin(x)x+ln(x)cos(x))

Step 3.7:

Simplify the expression.

Step 3.7.1:

Apply the distributive property: esin(x)ln(x)sin(x)x+esin(x)ln(x)(ln(x)cos(x))

Step 3.7.2:

Combine esin(x)ln(x) and sin(x)x: esin(x)ln(x)sin(x)x+esin(x)ln(x)ln(x)cos(x)

Step 3.7.3:

Reorder the terms for clarity: esin(x)ln(x)ln(x)cos(x)+esin(x)ln(x)sin(x)x

Step 4:

Formulate the equation by equating the left and right sides: y=esin(x)ln(x)ln(x)cos(x)+esin(x)ln(x)sin(x)x

Step 5:

Replace y with dydx to get the final derivative: dydx=esin(x)ln(x)ln(x)cos(x)+esin(x)ln(x)sin(x)x

Knowledge Notes:

To solve the given problem, we need to apply several calculus rules and properties:

  1. Chain Rule: This rule is used for differentiating compositions of functions. It states that ddx[f(g(x))]=f(g(x))g(x).

  2. Product Rule: This rule is used when differentiating products of functions. It states that ddx[f(x)g(x)]=f(x)g(x)+g(x)f(x).

  3. Exponential Rule: This rule is used when differentiating exponential functions. It states that ddx[ax]=axln(a), where a is a constant.

  4. Logarithmic Properties: These properties help to simplify expressions involving logarithms. For example, ln(xy)=yln(x).

  5. Derivatives of Basic Functions: The derivative of ln(x) with respect to x is 1x, and the derivative of sin(x) with respect to x is cos(x).

By applying these rules and properties systematically, we can find the derivative of the given function y=xsin(x).

link_gpt