# Thread: Finding the critical number.....

1. ## Finding the critical number.....

What is the critical number of the following problem:

x^10(x - 4)^9

I got 4,0,40/19

Any help
thx

2. Originally Posted by kashifzaidi
What is the critical number of the following problem:

x^10(x - 4)^9

I got 4,0,40/19

Any help
thx

That is correct: those three numbers are where the first derivative vanishes. Good!

Tonio

3. but these numbers are not accepted by my online hw website.

4. Originally Posted by kashifzaidi
but these numbers are not accepted by my online hw website.
The answers are correct for the function you posted. The reason why your on-line hw website is not accepting them is not something MHF can answer. Discuss this problem with your teacher.

5. Originally Posted by kashifzaidi
but these numbers are not accepted by my online hw website.

Who cares? they're still correct...unless you were asked to find the extrema points: maximum and minimum, which NOT necessarily are all the critical poitns though they're obtained from the critical points.

Tonio

6. here is the screen shot

7. Never Mind !!! I got this
thx

8. Originally Posted by kashifzaidi
Never Mind !!! I got this
thx
I'm happy that you got it. But I'm not happy that the valuable time of several people has been wasted simply because you did not post the full question. The fact that nature of the critical points was also required is an important part of the question that should have been included when you first asked the question.

9. Originally Posted by mr fantastic
I'm happy that you got it. But I'm not happy that the valuable time of several people has been wasted simply because you did not post the full question. The fact that nature of the critical points was also required is an important part of the question that should have been included when you first asked the question.

Indeed. I find it an appalling fact that so many university students are so sloppy when writing their questions...almost unbelievable, and it's a pity: I've flunked students for their nonsensical writing, and it's a maxima for me: when reading a paper/exam, anything that isn't clear is gonna be treated as erroneous, let alone scratches, arrows sending you two pages back or forwards, feet-writing, etc.
I'd rather have students with lousy spelling (which can be explained by many factors other than sheer ignorance) than without any capability to write two sentences making some sense.

Tonio