Finding Derivative, but wrong sign

In summary, finding a derivative with the wrong sign means that the direction of the slope at a specific point on a curve has been miscalculated, resulting in an incorrect answer. This is important because it can greatly impact the accuracy of calculations. Common mistakes that lead to this include miscalculating signs, forgetting to include negative signs, and making errors in algebraic manipulations. To prevent this, it is important to carefully check work and practice with different examples. If a mistake is realized, it is important to retrace steps and seek help if needed.
  • #1
gr3g1
71
0
Ok, I am doing my calculus homework, but sometimes I get a negative in the wrong place...
Here is an example:
The solution I got for the derivative attached is on the numerator:
5e^x(9e^x)-5e^x(4+9e^x)
In the solution, the negative sign is on the other side??
I don't get it
 

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  • #2
You are probably misapplying the quotient rule, which is:

[tex]\frac{d}{dx}\left(\frac{f}{g}\right)=\frac{f'g-fg'}{g^2}[/tex]

It does matter in which order you place the terms in the numerator.
 
  • #3
Damn!
I didnt know that! Thanks a lot man!
 

Related to Finding Derivative, but wrong sign

1. What does it mean to find a derivative with the wrong sign?

When finding a derivative, the sign indicates the direction of the slope at a specific point on a curve. If you find a derivative with the wrong sign, it means you have miscalculated the direction of the slope and your answer is incorrect.

2. Why is finding a derivative with the wrong sign important?

Finding a derivative with the wrong sign can lead to incorrect results and can greatly impact the accuracy of your calculations. It is important to pay attention to the signs when finding derivatives to ensure the correctness of your work.

3. What are some common mistakes that lead to finding a derivative with the wrong sign?

Some common mistakes that can lead to finding a derivative with the wrong sign include miscalculating the signs of the terms in the derivative equation, forgetting to include negative signs in front of terms, and making errors in algebraic manipulations.

4. How can I prevent finding a derivative with the wrong sign?

To prevent finding a derivative with the wrong sign, it is important to carefully check your work and double-check the signs of each term in the derivative equation. It can also be helpful to practice with different examples to become more familiar with the process.

5. What should I do if I realize I have found a derivative with the wrong sign?

If you realize that you have found a derivative with the wrong sign, it is important to retrace your steps and carefully check your work for any errors. If you are unable to find the mistake, seeking help from a teacher or tutor can be beneficial in understanding where you went wrong.

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