Help with questions about finding the coordinates

With this question , I tried substituting but I keep getting it wrong,
1/2 X + 1 = y
1/2 X + 1 = X² +4X +3
0=X²+3.5X+2
From there i can't factorized from here.

(This paper from the C12 IAL paper Jan 2016)

(edited 7 years ago)

Reply 1

ghostwalker

17

Original post by Cake_Chan

With this question , I tried substituting but I keep getting it wrong,
1/2 X + 1 = y
1/2 X + 1 = X² +4X +3
0=X²+3.5X+2
From there i can't factorized from here.

(This paper from the C12 IAL paper Jan 2016)

Fine so far.

You'll need to use the quadratic formula - it doesn't have a nice factorization.

Reply 2

Zacken

22

Original post by Cake_Chan

With this question , I tried substituting but I keep getting it wrong,
1/2 X + 1 = y
1/2 X + 1 = X² +4X +3
0=X²+3.5X+2
From there i can't factorized from here.

(This paper from the C12 IAL paper Jan 2016)

Not factorisable over the rationals. Use the quadratic formula.

Reply 3

Bigbosshead

2

Could they ask you to find this area?

If yes, what would you do after establishing the area of the trapezium?

Reply 4

JN17

10

The question is an error, the curve is meant to be x^2 -4x+3, we went over this exact question today in class ;p

Reply 5

JN17

10

Original post by Bigbosshead

Could they ask you to find this area?

If yes, what would you do after establishing the area of the trapezium?

Area of trapezium - integral of curve for QS - integral of curve for TP

Reply 6

Bigbosshead

2

What do you mean by integral curve for QS - TP?

Reply 7

Zacken

22

Original post by JN17

The question is an error, the curve is meant to be x^2 -4x+3, we went over this exact question today in class ;p

This was my paper. :facepalm:

Reply 8

imran_

2

theres nothing wrong with the paper, I did this earlier and got it right. However my method is very long but effective ;D

Find the area under the line of y=1/2x+1 with the intervals. (Let this be L)
then find the area under the curve of y+x^2+4x+3 with the intervals P and T
and then.... find the area under the curve of y=x^2+4x+3 with intervals Q and S and add those together. (Let this be R)

Finally L-R= ur answer

Reply 9

JN17

10

Original post by Zacken

This was my paper. :facepalm:

I've just checked an online version of the paper and it had it written as -4x, might have been a mistake that was seen after the exam but the question factorizes nicely with it and the area is much simpler.

Reply 10

Zacken

22

Original post by JN17

I've just checked an online version of the paper and it had it written as -4x, might have been a mistake that was seen after the exam but the question factorizes nicely with it and the area is much simpler.