i just came across this amazing website while searching for solutions and lessons on position vector and all i can do is open my mouth in amazement, whoever built this site deserves a nobel prize. it solve all maths problems by typing the exact question and even shows workings if you have a premium account. if you hate solving maths or just need a extra help, the site is www.mathway.com
they have an app for android and iphone too...

please note this is not some kind of ad, i'm just spreading the good/bad news