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Simplifying answers - FP1

Hello..

It seems that FP1 and C3 (The two modules I'm doing at the moment) involve a lot of simplifying to get the final answer. Although I had to do this in earlier modules, this is a lot harder.

For example, if you take a look at www.wolframalpha.com/input/?i=(1/4)n^2+(n%2B1)^2+-+(1/6)n(n%2B1)(2n%2B1)

The input being how my answer is at the moment, and the first alternate form being how the textbook has it.

How do they simplify this, and how do I get better at simplification in general? It's my downfall at the moment :/

Reply 1

nuodai

Normally it's just a case of taking out common factors.

In this case, you can take out

\dfrac{1}{12}n(n+1)

as a common factor (I chose 12 because it's the lcm of 4 and 6). Normally you then end up with another factor which contains a quadratic which you have to factorise. It's harder than what you'd expect to do in C1-2, but it's doable with C1-2 techniques.

The key (at least in FP1 summation questions) is just looking for common factors and then chomping through the algebra. With C3, it's more of the same really.