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To everyone who did GCSE Edexcel Mathematics Higher today...

There was a question. The squares and coordinates question.

Lots of people failed it and I want to know why you didn't get 21.5?

Do not simply just say X is 20. Show your working.

x1 and y1 is 6, 7 respectively
x2 and y2 is 38, 36 respectively.

x3 is 22. Work out y3.

The answer y3 is the answer you should've got in the exam.

I'll post a straight line so people can work it out.

Hint: Similar Triangles or Section Formula

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Reply 1
Here's the line
rip
(edited 5 years ago)
Reply 3
Reply 4
Original post by cmahesh13
I got something like like 20,22


DID I NOT JUST SAY "show your work".

This isn't helpful nor does it educate those who got the question wrong. I suggest you remove this or atleast put a spoiler
I think I got 22,20

The difference between the x values was 32. Divide it by 4. That gave you the length of the squares - 8

6 add 16 (8x2) = 22
36 take aqay 16 = 20
i did overall change in y and overall change in x. as the shape was made up of squares, i used the lines parallel to the x axis to figure out each side was 8 points (as the lines parallel to the y axis did not line up fully) This, given that the x was on the bottom corner of the second square down, meant it was the top corner, which was given as (38,36) - 2 sides worth of length (which is (16,16). This meant that the point was (22,20).
Reply 7
Original post by Goldfish4343
I think I got 22,20

The difference between the x values was 32. Divide it by 4. That gave you the length of the squares - 8

6 add 16 (8x2) = 22
36 take aqay 16 = 20


This is wrong but I completely understand why you might do that.
If you look at the line again you'd see that 29 is not equal to 32. Therefore you can't simply just take away 16.

You'd have to make 2 triangles, one with base 32 the other with base 16. The other with width 29 and the other with an unknown width.

32 / 16 = 2

29 / 2 = 14.5

7+ 14.5 = X (because it starts from 0)

Hope you understand!! x
Original post by ogerrana
This is wrong but I completely understand why you might do that.
If you look at the line again you'd see that 29 is not equal to 32. Therefore you can't simply just take away 16.

You'd have to make 2 triangles, one with base 32 the other with base 16. The other with width 29 and the other with an unknown width.

32 / 16 = 2

29 / 2 = 14.5

7+ 14.5 = X (because it starts from 0)

Hope you understand!! x


Where has 29 come from?
Original post by Goldfish4343
Where has 29 come from?




36-7 = 29


38-6 = 32

4 perfect circles so the side of one square of 32/4 which is 8.

This gives us the x coordinate which is 6 + (8*2 ) which is 22.
Original post by cmahesh13
36-7 = 29


38-6 = 32

4 perfect circles so the side of one squre of 32/4 which is 8.

This gives us the x coordinate which is 6 + (8*2 ) which is 22.

Now we know the difference in y is 29 so now we need to know how much is cut off. To do this we do 32-29 which is 3 and the we use to find that y = 20


The side of the squares were 8. X was two squares down from the top coordinate so you 36 - 16 = 20. I don't understand why the common answer and the one that makes sense is wrong.
it would be 21.5 if it was a straight line but its not
Reply 12
Original post by jkfdnas
it would be 21.5 if it was a straight line but its not


It is a straight line. You had to use section formula
Original post by ogerrana
It is a straight line. You had to use section formula


It wasn't a straight line though
Original post by ogerrana
It is a straight line. You had to use section formula


it wasn't because one pair of squares didn't meet at their corners, if it was a straight line the squares would have had no purpose in the question
Original post by ogerrana
It is a straight line. You had to use section formula


What evidence do you have that it's a straight line? Did you use any mathematical proof to prove collinearity or was it in the question? Or did you just "look" at the question paper? FYI, the instructions on the very front of the paper read "questions are not to scale unless otherwise indicated". So where did it indicate anything that warranted an assumption of collinearity?
good thing I did my maths gcse last yearrrrrr
It wasn't a straight line at all. The correct answer is 22,20.
If someone could draw a diagram of the question, with the squares and co ordinates marked on (not just the line), I will show how I got (22,20)
Original post by jkfdnas
it wasn't because one pair of squares didn't meet at their corners, if it was a straight line the squares would have had no purpose in the question


I don't get what's hard in this question.

Use the midpoint formula and you get x=21.5???

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