







Difference of squares 
19980623 

Kristen Smelsky pose la question : Solve the following using a difference of squares: 4x(squared) minus 4xy plus y(squared) minus m(squared) plus 2m minus 1 Penny Nom lui répond. 





The Birthday Problem 
19980612 

Josh Skolnick pose la question : if you are at a party what is the least amount of people that have to be there to have at least a 50% chance of having 2 people with the same birthday? and how do you get the answer thank you in advance josh Harley Weston lui répond. 





Rolling a seven 
19980611 

Bruce Thompson pose la question : What is the probablity of rolling two dice and it coming out as seven? a) 1/6 b) 1/36 please give me the correct awnser and explain please. Harley Weston lui répond. 





Grade 9 Algebra 
19980607 

Tarah Kostenko pose la question : I am a grade 9 student and I cannot figure out how to solve these two similar problems. can you please help? 3(y1/2)=1/2 also 2/3(x + 1)=6 I don't come up with the same answers as the book and I can't figure out what I'm doing wrong. Thank you,
Harley Weston lui répond. 





A Logic Problem 
19980607 

Anthony Bacigalupo pose la question : My name is Anthony Bacigalupo and I take Sequential ][ Math and am taking a practice regents. When doing a logic problem, I encountered the following statements, where I am trying to prove P ( I left out steps unrelated to the question).... Chris Fisher lui répond. 





A trig limit 
19980528 

Ann pose la question : This problem is a calculus 1 limit problemhigh school level. I'm teaching myself calc over the summer and I'm already stumped. find the limit lim sec^(2)[(sqrt2)(p)]1 p>0  1sec^(2)[(sqrt3)(p)] I'm Ann. Harley Weston lui répond. 





Sequences and series 
19980527 

Michael Le Francois pose la question : The sum of the first ten terms of an arithmetic series is 100 and the first term is 1. Find the 10th term. The common ratio in a certain geometric sequence is r=0.2 and the sum of the first four terms is 1248 find the first term. Penny Nom lui répond. 





Trigonometry history 
19980526 

Joeseph Huckler pose la question : Can you please tell me some history of the trigonometric ratio Tangent? who discovered it? when was it discovered and some other useful info... Penny Nom lui répond. 





A Place Value Curiosity 
19980525 

Ed pose la question : I was visiting with an elderly gentleman this afternoon. He showed me this curiosity and then asked if I could explain it to him. Can you provide an explanation of why the 9 or multiple of 9 keeps occurring in this procedure? Choose any number, say 125 and add the digits to get 8. subtract the 8 from the 125 and the result is 117. Add the digits in 117 to get 9. Subtract the 9 from the 117 to get 108. Add the digits in 108 to get 9. If this procedure continues a 9 or a multiple of 9 reoccurs. What is the mathematical explanation behind this happening? Denis Hanson lui répond. 





The Fourth Dimension 
19980524 

Whitney Page pose la question : Okay, here goes all my effort to try to explain shat I'm trying to ask of you. It's about something I read in a book called A WRINKLE IN TIME, by Madeline L'Engle. It's called tesser, or tesseract. It talks about first diminsion, a straight line, second diminsion, a flat square, and third diminsion, a square with sides, front and back, top and bottom. I can picture all of that. Then it says that fourth diminsion is when you square the three diminsional square. It also described the fourth diminsion as time. I can't figure out how that can be. Then it says... Chris Fisher lui répond. 





Percentage Question 
19980518 

Eddie Knox pose la question : Example: If I have a recipe calling for 16 ounces of 4% vinegar (vinegar which has been diluted with water to a strength of 4%), and all I have on hand is 16 ounces of 5% vinegar, how much water should I add to decrease the strength to 4%, before measuring the 16 ounces to be used. I'll appreciate any insight and help. Thank you so much! Harley Weston lui répond. 





Graph question 
19980512 

Rose Seminary pose la question : Why is the point of intersection of two lines the solution to the corresponding system of equations? Penny Nom lui répond. 





Isosceles trapezoid formula 
19980512 

Donna McMullin pose la question : The teacher of Gifted and Talented Math has been trying to locate the formula for anisosceles trapezoid and we can't find it anywhere. Could it be the same formula for that of a parallelogram ? Please advise. Walter Whiteley lui répond. 





Un angle solide 
19980506 

Giol pose la question : Qu'est ce qu'un angle solide ?? J'ai beau chercher dans mes documents, je ne trouve rien de bien convaincant sur le sujet si ce n'est une définition qui me semble bien vague et creuse ... En vous remerciant de votre attention ( puissiez vous illustrer votre réponse par un exemple, s.v.p...) Bonjour,
Chris Fisher lui répond. 





Area Calculation 
19980505 

Jessica pose la question : There's a question I have that I hope you can answer about calculating area. It seems to me that common sense says that if you have say 100 meters of fence, the area you can enclose should be a constant. Yet the math says it is not so. For example if you build a rectangle 10x40 the enclosed area is 400 square meters. But if you build a rectangle 5x45 then the area is 225 square meters, even though you've started with the same amount of fencing. I know this is true, but can anyone explain IN ENGLISH why this is so? Harley Weston lui répond. 

