Edexcel C3 June 2015 Question 8

A trig question for you !

Enjoy !

[SlaterFPS]

I know this is very old but people who don't understand what happens to the 2sinAcosA, here's what happens

If you see at 7:20, he is factorising the whole top line (cos^2A +sin^2A + 2sinAcosA) to (cos^2A + sin^2A)^2
which is actually (cos^2A + sin^2A)(cos^2A + sin^2A) you see you would get sin^2A and cos^2A but also 2sinAcosA.

If you still don't understand
It is like x^2 + 2x + 1, could be factorised to (x+1)^2 where
- x represents sinA
- 1 represents cosA
- 2x represents 2sinAcosA.

[zorjkpg]

Used this many years after it was made to help my son in his A levels. Thank you for your help, keep up the wonderful hard work and don't mind the bad comments, I wonder what they contribute to help other people!

[nahidahmed]

Appreciate your work thank you. just one criticism. please make the writing bigger. prehaps bring the camera closer or write bigger.

[anubhabdas]

i fucking hate my life rn- have 4 exams this week and cant do c3 for shit... im asian aswell- what a let down ;(

[TheDutchRiposte]

U didn’t fuckin explain it, u just wrote down what was on the mark scheme

[RazzaaRazzaa]

I wish I could block you, if you’re gonna do explanations don’t just do the low mark questions.