Find the derivative.

A

alexmay

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f(x)=7-(x^4 * e^x)

I need some help with working my way through this problem, and figuring out how to approach it. I would greatly appreciate it.
 
Have you learned the product rule?

Please show your work, so we can see what difficulty you are having.
 
\(\displaystyle \frac{d}{dx}[7-(x^4 * e^x)] = \frac{d}{dx}(7) - \frac{d}{dx}(x^4 * e^x)\)

Since \(\displaystyle (x^4 * e^x)\) is a product you should us the _______ rule to find the derivative of it.
 
Product rule, I got 4x^3 * e^x for my final answer
 
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alexmay said:
Product rule, I got 4x^3 * e^x for my final answer
Click to expand...
The problem is that the product rule does NOT say to take the derivative of the functions separately and then multiply the result.

What is the formula for the product?
 
Yeah that was a different problem, for this one I got this: I'm not sure if it's correct
Screen Shot 2020-03-03 at 5.15.20 PM.png
 
alexmay said:
Yeah that was a different problem, for this one I got this: I'm not sure if it's correct
View attachment 16987
Click to expand...
That is correct.

[MATH]w(x) = u(x) * v(x) \implies w'(x) = u(x) * v'(x) + u'(x) * v(x).[/MATH]
As for the problem in post # 6 (now deleted), we greatly prefer a separate thread for each problem, and telling us what the problem is an assistance when you ask whether an answer is correct.
 
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post #6 was posted in the wrong thread, I wasn't asking the question to this thread
 
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