C4 Edexcel A level 22nd June 2018 Unofficial Markscheme

Part Credz to my twin brother "chillichamps"


Post your answers here and i’ll edit
q1)if 1+3=6, then what is the integral of 1/4x+5x^1/3? rosemary cayenne pepper +c
Q1:

a) Use the bionmial series to find the expansion of ,

Answer:

b) Use your answer to part (a) to estimate the value of . Give your answer to 3 decimal places.

Answer: (3 decimal places)

Q2:

a) i) Find the values of A, B and C.

Answer:

a ii) Hence find ,

Answer:

b) Find .

Answer:

c) Using the substitution , find

Answer:

Q3:

a) . Find in terms of x and y.

Answer:

b) Hence find the x coordinates of the two points where

Answer: ,

Q4:

a) Show that . We could use the triangle to say that , therefore .

b) Assume the rate of increase of the volume of water in the cone is . Find the rate of change of the depth of water, leaving your answer in terms of .

Answer:

Q5:
, . The point P (k, 2) is a point of the curve with these parametric equations.

a) Find the value of k.

Answer: (note that

b) Find the equation of the tangent at P,. Give your answer in the form , where p and q are exact real constants.

Answer:

Q6:

Given that when , solve the differential equation

Answer:

Q8:

a) Find

Answer :

A sketch of C, is shown above, as is the finite region R between and . This region is rotated through radians about the x-axis to form a solid of revolution.

b) Find the exact value of the volume of the solid generated.

Answer:


-stationary points: 1+-sqrt2
-rate of change of depth=8/3pi
-integral= 3/8lnu(5+4x^2/3)
-vol of revolution=0.68 (not exact i know) included pi^3 and pi
-binomial expansion=17.6- let x=0.1 and then times by 10

k=6-pi/2
-lambda=-8/5
cos(x)=4/sqrt21
area=12sqrt5

You know the the substitution question, did it ask you to turn the U back into X

I got -5/2 for the lamda

Thanks how much was it out of tho?

how many marks was part a and b for that question? I think a was 2, but can't remember b.

Made the same mistake

It was 2 marks for part a and 5 marks for part b

I agree with all this, except I think lambda was -5/4 and Q was (4,8.5,5.5)

Grade boundary predictions?

do you want to tell us the answer then

I agree with all this, except I think lambda was -5/4 and Q was (4,8.5,5.5)

Here are my worked solutions to Qs 1 to 4 of the paper. The rest after lunch.

how many marks was part a and b for that question? I think a was 2, but can't remember b.

Made the same mistake