2016 Edexcel C2 Morning exam[discussion thread]

it was absolutely nightmare

What did everyone get when substituting their x value into the 2nd differential to show it was a minimum point? (very last question part e)

I got a really small decimal??

2^(2x+5) laws of indices allow you to rewrite this as (2^5)(2^2x). Then as 2^2x= (2^x)^2 so this bit equals y^2. So you get 2^5 lots of y which is 32y^2.

When does BTEC maths start?

Any mark scheme up?

awesome thanks,

so you get 32y^2 -7y=0, and then solve like a regular old equation.

y(32y-7)=0

y=0
y=7/32
so then 2^x=0
and also 2^x=7/32

log(base2) (0) cant be done
so log(base2)(7/32)=x

Awesome, i've been looking through the mark schemes people are talking about and i'm pretty sure ive got everything else right, so 71/74 for me!

can someone put up a link to arseys solution

how did we find it all?

like the differentiation question?

haha you're dumb

My answers:

1 b) (2 marks) $256$
c) (2 marks) $1.602$

2 a) (1 mark) $7$
b) (3 marks) $20.75$
c) (2 marks) $5.75$

3 a) (2 marks) $\sqrt{34}$
c) (4 marks) $3x+5y-95=0$

4 a) (2 marks) $5$
b) (2 marks) $f(-2)=0$
c) (4 marks) $f(x)=(x+2)(3x+2)(2x-1)$

5 a) (4 marks) $16-288x+1944x^2$
b) (1 mark) $16$
c) (2 marks) $\frac{7}{2}$

d) (2 marks) $936$

6 i) (3 marks) $\frac{8\pi}{15}$or $\frac{-2\pi}{15}$

ii) (6 marks) or

7 b) (3 marks) $24.3$

8 ii) (4 marks) $-2.19$

9 a) (2 marks) $\frac{\pi x^2}{3}$
d) (5 marks) $x=16.63$ $P= 120m$
c) (2 marks) $f''x = 0.437$

my unofficial mark scheme

Note that question 6) ii) , had 3 values, original value for x was -14.4 but you also get 14.4. You may want to check that.