Math Is Fun Forum

Thanks... i have edited by calculations! Im also wondering... how do you get the letters to look like normal letters - like you have for 'm'. I took mathsy's advice and looked at the code, but i didnt understand what was going on!

Thanks all of you... just wondering.. could it be done by calculating the curved perimeter of the major segment and multiplying by 40? .. because isnt the curved surface area like a rectangle anyway?

Thats a really good idea! We have been given quite a lot of past papers, especially in maths (14!). So ive been rushing through each one in about an hour, making stupid mistakes... but your way is a much better way! Ive also started to miss out the easy questions at the beginning, and concentrate on the more difficult ones at the end. Thanks.

Oh yeh, i forgot about similarity!

I mainly related them to the spread, consistency, accuracy etc.

Of course... I will be happy to:

1. 24 ÷ 1/3 = 24/1 x 3/1 = 72/1 = 72

2. 0.3 x 0.3 = 0.3 x 0.1 x 3 = 0.03 x 3 = 0.09

3. 15 x 100² = 150000cm² (or 3m x 5m = 15m², so 300cm x 500cm = 150000cm²)

4. Undefined?? 8 ÷ 4 is 2, because 2 x 4 is 8. But if you divide 1 by 0, there is no number that 0 can be multiplied by to give 1?

5. I dont know off the top of my head, but if i draw the curve with the values i do know (sin30=0.5, sin90=1, sin180=0 etc), then i guess it is around 0.75ish?

Another way could be to use a right-angled isosceles triangle with sides 1, 1, and √2.
If sin45 = opposite/hypotenuse
   sin45 = 1 / √2
to rationalise the denominator: 1/√2 x √2/√2 = (√2)/2
I know that √2 is roughly 1.41, so sin 45 ≈ 0.705? (shows my graph was a bit rubbish!)

Im not 100% about these last 2...

Another factor that suggests the rate of expansion is increasing is red shift. When we look at light from distant galaxies, we find that all the frequencies are shifted towards the red end of the spectrum. In other words, the frequencies are all slightly lower than they should be. It's the same effect as a car horn sounding lower-pitched when the car is travelling away... this is known as the Doppler effect. Measurements of the red shift suggest that all the galaxies are moving away from us very quickly - and it's the same in whichever direction you look in. However, more distant galaxies have greater red shifts than nearer ones - which means that the more distant galaxies are moving away faster than nearer ones. Following the pattern, it is almost definite that galaxies even further away (ones which we cannot see) are moving away even faster (otherwise nearer ones would collide with them). So if the further galaxies are moving away faster, then the further out you go, the faster the rate of expansion - so the universe is expanding with an increasing rate.

Yeh i did... its really good! the revision parts arent too great, but the past questions were really helpful thanks! I also had a look at the A-level stuff, but ive decided to wait until after my exams to do it. So in the summer i will get as far ahead as i can, so i can always be pushing myself in class. I might need you guys' help though to try and teach me some of the work . Oh Devantè, by the way... I'm a full member now ! 50 posts it was!

Was number 10 a normal find the longest word one??? If it was...

:):):):):):):):):):):):):):)

Thank you! that was really well explained. Ive realised the problem i have is deciding how to go about solving it - once you said to look at the LHS and find two numbers that multiply to give 500,050 i could do the rest myself. So ive learnt... if i see 'using this result', make sure i do actually use it! Thanks

Thanks :):):):):):):)! would you mind having a look at the question i posted in the help me section? its got me baffled!

Oh well... im not too far off 50! 45ish i think!