What is the Derivative of sin x^5?

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Homework Help Overview

The discussion revolves around finding the derivative of an integral involving the sine function, specifically the integral of sin(t) with variable limits defined by x^5. The subject area includes calculus, particularly the application of differentiation and integration techniques.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants explore the correct interpretation of the integral's limits and the differentiation process. Questions arise regarding the application of Leibniz's rule for differentiating integrals with variable limits. Some participants clarify the steps involved in integrating and then differentiating the result.

Discussion Status

There is an ongoing exploration of the problem, with participants providing insights into the correct approach to differentiate the integral. Some guidance on using Leibniz's rule has been mentioned, indicating a productive direction in the discussion.

Contextual Notes

Participants note confusion regarding the notation used in the original post, particularly the use of 'o' instead of '0' for limits of integration. This has led to clarifications about the integral's setup and the need for precise notation in mathematical expressions.

char808
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Find the derivative.

d/dx \int\stackrel{x^5}{o} sint dt

I came up with sin x^5.

The answer is 5x^4 sin (x^5).



Not sure what I'm missing here.
 
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Is the question:

Integrate x^5*sin(t) with respect to 't', then differentiate the result with respect to 'x'?
 
x^5 and 0 are the limits, right?

First: you integrate sint with respect to t.
Second: Apply the limits to the value you obtained for the integer. You'll get two terms, get it?

Then, derive this result with respect to x.
 
emol1414 said:
x^5 and 0 are the limits, right?

First: you integrate sint with respect to t.
Second: Apply the limits to the value you obtained for the integer. You'll get two terms, get it?

Then, derive this result with respect to x.

That works in this problem but the point is likely to use Leibnitz rule for differentiating an integral with variable upper limit. It would work even if you had something more difficult than sin(t) that you couldn't find the antiderivative for. The basic Leibnitz rule is:

\frac d {dx}\int_a^{g(x)} f(t)\, dt = f(g(x))\cdot g'(x)
 
The repaired LaTeX is below.
char808 said:
Find the derivative.

d/dx \int\stackrel{x^5}{o} sint dt

I came up with sin x^5.

The answer is 5x^4 sin (x^5).



Not sure what I'm missing here.

d/dx \int_0^{x^5} sint dt
To the OP: click the integral to see the LaTeX code I used.
The integral in the original post was confusing to at least one person who didn't understand that x5 was one of the limits of integration.

Also, don't use o (the letter) where 0 (the numeral) is intended.

BTW, there is no such word as "intergral" - the word is integral.
 

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