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Petrus
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Hello MHB,
I got problem to antiderivate \(\displaystyle \frac{8x^2}{x^2+2}\)
Regards,
I got problem to antiderivate \(\displaystyle \frac{8x^2}{x^2+2}\)
Regards,
I get \(\displaystyle 8- \frac{16}{x^2+2}\) it should be correct.Ackbach said:I would probably go for polynomial long division here. What do you get?
Petrus said:I get \(\displaystyle 8- \frac{16}{x^2+2}\) it should be correct.
I only get .. \(\displaystyle 8x-\frac{8}{x}\ln(x^2+2)\) and that is wrongAckbach said:That's what I get, too. And you can check it by simply getting a common denominator and adding back up. So where do you go from here?
Petrus said:I only get .. \(\displaystyle \frac{8}{x}\ln(x^2+2)\) and that is wrong
\(\displaystyle 8x-\frac{16}{\sqrt{2}}\arctan(\frac{x}{\sqrt{2}})-16C\) is that correct?Ackbach said:You have to integrate term-by-term now. You have
$$\int \left( 8- \frac{16}{x^{2}+2} \right)dx
=\int 8 \, dx-16 \int \frac{dx}{x^{2}+2}.$$
Surely you can do the first one. Can you recognize what the second one is?
Petrus said:\(\displaystyle 8x-\frac{16}{\sqrt{2}}\arctan(\frac{x}{\sqrt{2}})+C\) is that correct?
Petrus said:Hello.
I get same answer when I derivate so it's correct! This just show that I should train more antiderivate/derivate! Better early then later!:)
Regards,
Hello Ackbach,Ackbach said:The more correct words in English are that you "get the same answer when you differentiate". Better words are "differentiate" and "anti-differentiate" or better yet, "integrate".
Ackbach said:You have to integrate term-by-term now. You have
$$\int \left( x- \frac{16}{x^{2}+2} \right)dx
=\int x \, dx-16 \int \frac{dx}{x^{2}+2}.$$
Surely you can do the first one. Can you recognize what the second one is?
Prove It said:No, the integral was actually \(\displaystyle \displaystyle \int{8 - \frac{16}{x^2 + 2}\,dx} \).
An antiderivative is a mathematical function that is the reverse of a derivative. It is also known as the indefinite integral of a function.
An antiderivative and a derivative are inverse operations. A derivative tells us the rate of change of a function at a specific point, while an antiderivative tells us the original function from which the derivative was taken.
To find an antiderivative, you can use integration techniques such as the power rule, substitution, or integration by parts. These techniques involve manipulating the function to find a simpler function whose derivative is the original function.
No, not all functions have an antiderivative. Some functions, such as exponential or trigonometric functions, do not have an elementary antiderivative. In these cases, we use more advanced techniques such as numerical integration.
A definite antiderivative has specific limits of integration and gives a numerical value, while an indefinite antiderivative does not have limits and gives a general expression for the antiderivative.