c1 paper help

the points A (1, 7) B (20, 7) C (p, q) form the vertices of a triangle ABC. the point D (8, 2) is the midpoint of AC.

a) find the value of p and q

the line L passes through D and is perpendicular to AC intersects AB at E.

b) find an equation for L

c) find the exact x coordinate of E

help will be much appreciated! :yep:

Sana x

Reply 1

refref

Have you drawn a diagram?

Reply 2

just_sanaa

ShortRef

Have you drawn a diagram?

yehh heres the diagram ....

Diagram.docx31.3KB

Reply 3

just_sanaa

zdo0o

did these in my head so not sure if they're right,

15,-3

y=14/10 x + 6.6

x=0.4/1.4

coudl you check the mark scheme pls if theyre right ill write out my method

i would if i had the markschemes lol. but if u look at the diagram i posted in the previous post, it doesnt seem like 15,-3 cud be the coordinates :s-smilie:

Reply 4

Ejit

a) use the midpoint formula (I got (15,-3) also)
b) use the gradient formula for AC, and know that the gradient multiplied by the perpendicular gradient will equal -1, subsitute values
c) simultaneous equation

I don't know if that helps, but you didn't give much of an impression where exactly you were stuck.

Reply 5

just_sanaa

zdo0o

but you drew those cooirdinates without knowing p and q?

D is the midpoint of AC

A --> D is, move 7 along x axis, 5 down y axis.
therefore
D --> C must be the same process, since it's the midpoint. 7 along, 5 down, and you reach 15,-3

EDIT: in fact if you look at your diagram, your line AD is longer than DC, if you make DC the same length it fits to 15,-3 exactly xD

actualli yes i see your point. i mustve misread the coordinates or something but your explanation makes sense. i wish id thought of that haha!

its edexcel jan 05 but its very hard to find the markschemes. our schools gonna give them when we get bk to school.

so how would you do the other ones? assuming ur answers are right?

Thanks for ur help! x

Reply 6

just_sanaa

zdo0o

Attachment not found

that's the mark scheme for the jan 05 edexcel c1 paper :smile:

lol ok i get that. thankyou soo much for ur help and time!!! i am in debt to you lol! if you need any help, not that you would, but i could always try! loll

also thanks for the markscheme!

xxxx

Reply 7

Nosh_0306

Thank you soo much this helped a lot!