Cosine rule?

Showing 1 to 4 of 4

Has anyone got a good way to remember the cosine rule for angles beacuse i dont think they gve you that in the exam?

Thanks :)

Posted: 03-06-13 13:53 by :) PurpleJaguar (: - Team GR

no they dont give it to you in the exam 

Posted: 06-06-13 19:16 by bella

They give you the rule in the GCSE exam, but not in A Level. I think the best way to learn it would be to practice, over and over again. Write it down as much as you can bear; the more you get used to using it, the easier it will be to remember.

Posted: 02-11-13 21:55 by Shannon Tennant-Smith - Team GR

Well the rule is a2 = b2 + c2 - 2bc CosA. I always remember it as the letter for the side you are calculating will be the same as the letter for the angle (so a and A). remembering it as abc for the first part "a2 = b2 + c2" or something. There's no easy way of remembering it, but repeatedly using it in practice questions would help you remember it. :)

Posted: 03-11-13 15:33 by Tilly - Team GR