Edexcel A2 C3 Mathematics 12th June 2015

growl all you want YOU ARE STILL A DUMMY

why have you worked from right to left? is that even allowed? i thought its always prove left to right

why have you worked from right to left? is that even allowed? i thought its always prove left to right

Trig identity: how i did it...
split thing into 1/cos2x + sin2x/cos2x
then make common denominator of cos2x so it is (1+sin2x)/cos2x
then expand the double angle formulae so (1+2sinxcosx)/(cosx)^2 -(sinx)^2
then factorise denominator (diff of 2 squares) so
(1+2sinxcosx)/(cosx + sinx)(cosx - sinx)
using identity (sinx)^2 + (cos)^2 =1, sub in the sin and cos parts so you get
((sinx)^2 +(cosx)^2) +2sinxcosx)) / (cosx + sinx)(cosx - sinx)
the numerator can be factorised to (cosx+sinx)(cosx +sinx),
so now u have (cosx+sinx)(cosx +sinx) / (cosx + sinx)(cosx - sinx)
and then one of the (cosx + sinx) brackets cancel with the one on the bottom leaving u with (cosx + sinx) / (cosx -sinx)
sorry for it being hard to read...

I would agree it was trickier compared to previous years papers (except June 13 which was harder by miles). All I'm saying is that there was nothing on that paper which would have thrown a well prepared candidate off. My further maths class found it to be a reasonable paper.

57 for A* june 2013 ...
but is june 2015 as hard as 2013???
Or about the same.

the equation of the asymptote for the first graph was y=-5, was there an asymptote for the second graph? If so what was the equation.

Hi, I also had a brain freeze but I got it as 3cosx +sinx and put it in Rcos(x+a) form- I know I got thr right answers but will I still get the marks for not using tan?

about 33

I forgot to write the asymptote. Would just lose 1 mark each?

Did anyone get tanA=1/3

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