# Recent content by qwerty44

1. ### ITT: Post Mathematics (2U) Questions/Problems

When doing any calculus (differentiation or integration) with trig function you use radians. Because degrees are not a linear measurement.
2. ### Series and Sequences - Sum of a series

Use simultaneous equations with variable a and d. Then when you solve for a and d just find the sum when n=20 i.e. a+5d=23 a=23-5d (1) 10/2(2a+9d)=210 (2) sub (1) in (2) Solve.
3. ### How big is the observable universe? Find out here....

haha don't thank me, thank the guys who made it. It will keep you occupied for a while too :D
4. ### How big is the observable universe? Find out here....

Also make sure you click on things as it gives you some information.
5. ### How big is the observable universe? Find out here....

No worries :D
6. ### How big is the observable universe? Find out here....

You will make no mistake in clicking this link, as it is quite interesting even for non-physicist: http://htwins.net/scale2/
7. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon That's true. Some people read solutions and think they understand, but when you give them a similar question, they have no idea.
8. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon Good question. Also realised your source of questions :P
9. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon I'm a bit late, but yes, 5kg. :D
10. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon A mushroom farmer has sent an order of 70 kg of mushrooms to the markets in standard cases. If he had used larger cases, each capable of holding 2 kg more, he would have used 4 fewer cases. What is the capacity (in kg) of the standard case?
11. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon It's called LaTeX. http://www.codecogs.com/latex/eqneditor.php <you can try it out here To post with it on here [ TEX ] *put code in here* [ / TEX ] without any spaces in the brackets. You'll~get~used~to~it
12. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon Another thing you should keep in mind is that the side length of an equilateral triangle inscribed in a circle of radius R is R\sqrt3. This can be proved later with calculus. So in this case, R*sqrt3=1, therefore R=1/sqrt3 (0.577...) Just an...
13. ### 2012 Year 9 &10 Mathematics Marathon

Re: 2012 Year 9 &10 Mathematics Marathon Correct :D
14. ### Cool problem of the day!

The least common multiple of positive integers a, b, c and d is equal to a + b + c + d. Prove that abcd is divisible by at least one of 3 and 5.
15. ### Cool problem of the day!

I got 30 units^2. Anyone else care to try?