 |
|
|
|
|
|
|
|
|
Trig identity crisis |
2000-11-29 |
|
Rhiannon pose la question :
I have tried many times to find the answer to these problems but I can't I am in grade 12 - tan(x)=csc2(x)-cot2(x)
- cos(x)/csc(x)-2sin(x)=tan(x)/1-tan(x)
- cos(x)[ tan2(x)1-1]/cos2(x)+sin2(x)=sec(x)
Harley Weston lui répond. |
|
|
|
|
|
|
Vector Problem |
2000-11-27 |
|
Ben pose la question :
An aircraft can fly 260km/h in still air and the wind is blowing at 70km/h towards the West. In what direction should the aircraft head so that its actual velocity is on a bearing of 030 degrees?
Harley Weston lui répond. |
|
|
|
|
|
|
Power series representations |
2000-11-27 |
|
Grace pose la question :
Is there a systematic way of finding a power series representation of a function? I understand that you have to manipulate the function so that it is of the form 1/(1-x), but beyond that I am lost.
Harley Weston lui répond. |
|
|
|
|
|
|
Order of operations |
2000-11-26 |
|
Margaret Pratt pose la question :
My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+1-5= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated.
Penny Nom lui répond. |
|
|
|
|
|
|
A complex calculation |
2000-11-24 |
|
Angie pose la question :
Multiply (3-2i)2=32-2(3)(2i)+(2i)2
Penny Nom lui répond. |
|
|
|
|
|
|
A piecewise linear equation |
2000-11-24 |
|
Jacky pose la question :
There is a light bulb and it is given that the light bulb cost $0.75 and the cost of operating it is $0.0081 per hour. From the information give, I came up with the linear equation: Let c be total cost and Let h be hours used. Therefore: c = 0.0081h + 0.75 represents the total cost of the light bulb and the electricity. However, the second part of the question added the fact that the light bulb will only last for 800 hours. If the light bulb is replaced as soon as it burns out exactly after every 800 hours, how can I write an equation that represents that? Is it possible? What would it look like on the graph.
Harley Weston lui répond. |
|
|
|
|
|
|
racine carrée |
2000-11-24 |
|
G. Bigorgne pose la question :
Quel est donc l'origine de l'expression "racine carrée" ? Pourquoi avoir choisi cette expression ?
Claude Tardif lui répond. |
|
|
|
|
|
|
What are adjacent angles that equal 360 called? |
2000-11-22 |
|
David pose la question :
I know that supplementary angles add to 180 degrees and that commplementary angles add up to be 90 degrees, but what are adjacent angles that equal 360 degrees called?
Chris Fisher lui répond. |
|
|
|
|
|
|
Comparing an integral and a sum |
2000-11-21 |
|
Douglas Norberg pose la question :
A fellow teacher asked me about a problem she wanted to give to her students. It involved whether to take a million dollars or a penny doubled a number of times. I was able to determine the number must have been .01 * 230 which is about $10 million and a lot more than $1 million. To check that I was right I used a spreadsheet and did a Riemann sum. When I finished I reasoned that I had done the task in several steps and I could have done it in 1 step. Thus I integrated .01 * 2x from 0 through 30 but the number I got was $15,490,820.0324. Why the difference?
Harley Weston lui répond. |
|
|
|
|
|
|
5 spades |
2000-11-21 |
|
Matt pose la question :
In a standard deck of 52 card how many would you have to draw (without looking at them) to be absolutely certain that you had 5 spades?
Claude Tardif lui répond. |
|
|
|
|
|
|
Range of a function |
2000-11-21 |
|
David Bell pose la question :
Given a rational function such as f(x) = (8x-3)/(4x-1). How can the range be found.
Penny Nom lui répond. |
|
|
|
|
|
|
Net, gross and vat |
2000-11-20 |
|
Chris pose la question :
I have my gross but want to find out the net so I know how much the VAT is?
Penny Nom lui répond. |
|
|
|
|
|
|
Integral solutions |
2000-11-20 |
|
David pose la question :
determine all pairs of integers (x,y) which satisfy the equation 6x2 - 3xy - 13x + 5y = -11 I got y= (6x2-13x+11)/(3x-5) and i don't konw how to continue
Claude Tardif lui répond. |
|
|
|
|
|
|
Permutations vs. combinations |
2000-11-20 |
|
Ashleigh pose la question :
How do you tell whether the problem is a permutation or a combination?
Walter Whiteley lui répond. |
|
|
|
|
|
|
Bridges and parabolas |
2000-11-18 |
|
Lauren pose la question :
My name is Lauren, and Im a secondary school student in Ontario. For my gr11 advanced math class I have to find out how and why parabolics are used in arch bridges and write 3 paragraphs on it. People who cohse satelites and whatnot are lucky - I've found a ton of info, but for arch bridges there seems to be nothing.
Harley Weston lui répond. |
|
|
