How Do You Differentiate y = sin(x)^x Using Natural Logs?

In summary, to find the derivative of y=sin(x)^x, we can use the natural log and the chain rule. By setting u=sin(x), we get y=ln(u). Then, using the chain rule, we can find dy/dx by evaluating (dy/du)(du/dx). In this case, dy/du = 1/u and du/dx = cos(x). Substituting back in for u, we get dy/dx = (1/sin(x))(cos(x)). Simplifying, we get dy/dx = cos(x)/sin(x), which is the same as ln(sin(x)).
  • #1
gyza502
4
0

Homework Statement


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


My teacher said to use Natural long to solve this.

she got,
step 1:ln(y)=ln(sin(x)^x)=x ln(sin(x))

step 2:y(dy/dx)=1(ln(sin(x)+x(cos(x)/sin(x)

Final answer:dy/dx=((sin(x))^x)[ln(sin(x))+x(cos x/sin x)

I don't understand how she derived ln sin(x) to be cos(x)/sin(x)...
 
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  • #2
gyza502 said:

Homework Statement


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


My teacher said to use Natural long to solve this.

she got,
step 1:ln(y)=ln(sin(x)^x)=x ln(sin(x))

step 2:y(dy/dx)=1(ln(sin(x)+x(cos(x)/sin(x)

Final answer:dy/dx=((sin(x))^x)[ln(sin(x))+x(cos x/sin x)

I don't understand how she derived ln sin(x) to be cos(x)/sin(x)...
Hello gyza502. Welcome to PF !

Use the derivative of the natural log, along with the chain rule.
 
  • #3
Let u= sin(x) so that y= ln(u)

By the chain rule, dy/dx= (dy/du)(du/dx).

What is dy/du? What is du/dx? Be sure to express every thing in terms of x, not u.
 

FAQ: How Do You Differentiate y = sin(x)^x Using Natural Logs?

How do I use natural logs to derive a function?

Natural logs, or ln, can be used to derive a function by taking the derivative of the function using logarithmic differentiation. This involves rewriting the function using ln and then using the chain rule to find the derivative.

What is the difference between logarithmic differentiation and regular differentiation?

The main difference is that logarithmic differentiation involves using ln to rewrite the function and then applying the chain rule, while regular differentiation only uses the basic rules of differentiation. Logarithmic differentiation is often used for more complicated functions that cannot be easily differentiated using regular methods.

Can natural logs be used to solve exponential functions?

Yes, natural logs can be used to solve exponential functions by using the inverse relationship between ln and e. By taking the ln of both sides of an exponential equation, you can isolate the variable and solve for its value.

What are the common mistakes made when using natural logs for derivation?

One common mistake is forgetting to use the chain rule when differentiating a function with ln. It is also important to remember to use the ln rules, such as ln(ab) = ln(a) + ln(b), when rewriting the function. Additionally, not understanding the properties of ln and e can lead to errors in the derivation process.

Are there any other applications of natural logs in mathematics?

Yes, natural logs have many applications in mathematics, including in solving exponential and logarithmic equations, finding the area under a curve, and modeling growth and decay in various fields such as finance, biology, and physics. They are also commonly used in calculus and other advanced mathematical concepts.

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