Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrong

1(a)6x+4
(b)-2/3
(c)x<-2/3
2(a)(i)u2=40
(ii)u3=28,u4=33
(b)(i)u5=35
(ii)851
3(a)3x²-13x-30=0
(b)(i)6, -3/5
(ii)reject -3/5 as log negative is invaid
4(a)A=55
(b)H=55(e^(-0.136x))+30
5(a)Show that k=12
(b)(0,-28)
6(a)-(2y+3x²)/(6y+2x)
(b)13x-11y+81=0
7(a)Show that AD//BC
(b)6.99 8(a)2√17 cos(x-1.326)
(b)9√17, 1.326
9(a)Show that y=6ln(x+5)
(b)3x-25y=-150ln5
10(a)(2k+3)/(x+4)+(k-3)/(x-2)
(b)(21/ln5)-6 11(a)1/9-2/27x+1/27x²
(b)0.03304
(c)6ln(17/16)-45/136
12(a)Show that dh/dt=λ/√h
(b)h^(3/2)=0.513t+1.728
(c)18.4
13(a)5000
(b)3 because |x-3|
(c){t:0≤t<3/5∪t>13/5}
14(a)sin2θ(23cos²θ-8cosθ-15)=0
(b)360°,540°,491°
15)Consider sinx>0 and cos x<0 for obtuse

For 15, I got to sin2x>0 by expanding the bracket, could be wrong though, probs multiple methods.

For 15, I got to sin2x>0 by expanding the bracket, could be wrong though, probs multiple methods.

For 15, I got to sin2x>0 by expanding the bracket, could be wrong though, probs multiple methods.

For 15, I got to sin2x>0 by expanding the bracket, could be wrong though, probs multiple methods.

How many marks was subscriber question (Q13)

is there another value for 14b of 450° as it's the sin2x graph for [360,540] ?

10

In the q it said x≠ 450

In the q it said x≠ 450

is there another value for 14b of 450° as it's the sin2x graph for [360,540] ?

12c isn’t 18. You had to 5-1.44 then input that value of h. H wasn’t 5

360 540 and 490 something

12c isn’t 18. You had to 5-1.44 then input that value of h. H wasn’t 5