7 items are filed under this topic.








Some nondecreasing sequences 
20150413 

From Sky: Hi I'm a Student and i'll try my best to state the problem perfectly.
The number of nondecreasing sequences of size at least 1 and at most N,
such that each element of the sequence lies between L and R, both inclusive.
Eg: N=1 L=4 R=5
ans= 2. [{4},{5}]
N=3 L=4 R=6
ans= 19. [{4},{5},{6},{4,4},{4,5},{4,6},{5,5},{5,6},{6,6}
{4,4,4},{4,4,5},{4,4,6},{4,5,5},{4,5,6},{4,6,6},{5,5,5},{5,5,6},{5,6,6}
,{6,6,6}] Answered by Claude Tardif. 





A sequence or a series? 
20130905 

From Rahul: Whether the following sequence is increasing or decreasing? I even do not kow whether to call it a sequence or not. an = (1/(1+n))+(1/(2+n))+....+(1/(n+n)).
I am confused. It looks like a series to me. Please help.
Regards,
Rahul Answered by Robert Dawson. 





Decreasing numbers 
20110413 

From Hadi: A number is called a "decreasing number" if each digit in the number is less than the digit to its left.
For example, 87420 is a deceasing number. How many fivedigit
decreasing numbers are there? Answered by Claude Tardif. 





A curve sketch 
20071122 

From Ahson: Find critical points, determine the monotonicity and concavity and sketch
a graph of f(x) with any local maximum, local minimum and inflection
points labeled:
1. f(x) = x^4  x^3  3x^2 + 1 Answered by Harley Weston. 





Increasing and decreasing for functions 
20071109 

From David: Direction: Identify the open intervals on which the function is increasing or decreasing.
f(x)=1/(x^2)
f'(x)= 2/(x^3)
i understand how to get up until there, and the undf. is x=0, but now i'm having problem setting up the number table chart. i cant remember how, and where to place the increase and decrease +  the
chart, for example <0> where would the increase and the decrease be place? Answered by Harley Weston. 





f(x) = (x^4)  4x^3 
20070722 

From Michael: I'm a student who needs your help. I hope you'll be able to answer my question.
Here it is: Given the function f(x)=(x^4)4x^3, determine the intervals over which the function is increasing, decreasing or constant. Find all zeros of f(x) and indicate any relative minimum and maximum values of the function.
Any help would be appreciated. Thank you for your time. Answered by Harley Weston. 





8digits numbers with their digits in decreasing order 
20060509 

From Headmaster: How many 8digits number are there with their digits in decreasing order Answered by Penny Nom. 


