







On what day of the week did 1994 begin? 
20150405 

tayyaba pose la question : there were 365 days in the year 1993
the first day of the year was friday.
on what day of the week did 1994 begin? Penny Nom lui répond. 





The derivative of sin(x) 
20140426 

Lucky pose la question : f(x)=Sin(x), by first principle its f'(x)...show me how to solve such problem. Penny Nom lui répond. 





Cumulative Frequency Math Question 
20130320 

Primadonna pose la question :
Hi,
Please help me solve this question.
Thank you so much.
The cumulative frequency table below shows the length of time that 30 students spent text messaging on a weekend.
Minutes Used 
Cumulative Frequency 
3140 
2 
3150 
5 
3160 
10 
3170 
19 
3180 
30 
Which 10minute interval contains the first quartile?
(1) 31–40
(2) 41–50
(3) 51–60
(4) 61–70 Penny Nom lui répond. 





The derivative of x^(1/2) 
20120114 

Eric pose la question : I have an problem figuring out the derivative of the negative square root of x i.e. x^(1/2) using the first principle.
Could someone please show me?
Thanks in advance! Harley Weston lui répond. 





Solving arithmetic problems in the right order (BEDMAS) 
20071005 

Kim pose la question : 3+4x2(10 divided by 5)= what? Penny Nom lui répond. 





Differentiate x^(1/3) using first principles 
20070914 

Sheila pose la question : our teacher gave us this question as a challenge and even he couldnt figure it out:
Differentiate x^(1/3) [aka the cube root of x] using first principles. i know the answer is 1/(3.x^2/3), but how is it possible using first principles? Harley Weston lui répond. 





Two sequences that agree in the first 4 terms 
20030526 

A student pose la question : Is it possible to have two formulas that define sequences that agree on the first four terms but not the rest? Penny Nom lui répond. 





Sequences that agree on their first four terms 
20020516 

Mike pose la question : Are there two formulas that define sequences that agree on their first four terms, but differ on the fifth term and all succeeding terms? Chris Fisher lui répond. 





zero 
20000101 

Jason pose la question : What civilization first used zero? Penny Nom lui répond. 

