Hello

I am wondering how i establish where to draw this line?

Question
22
The grid opposite shows the graph of y = x2 + 3x 2
(a) By drawing an appropriate straight line on the graph solve the equation

x
2 + 3x 3 = 0
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(2 marks)

(b) By drawing an appropriate straight line on the graph solve the equation
x2 + 2x 1 = 0

graph can be seen on page 22 here:

http://store.aqa.org.uk/qual/gcse/qp...W-QP-JUN05.PDF

2. Let $f(x)=x^2+3x-2$

Then, $g(x)=x^2+3x-3=x^2+3x-2-1=f(x)-1$

$g(x)=0\Rightarrow f(x)=1$

So, draw a line parallel to Ox, through y=1 and the x-coordinates of the intersection points are the solutions of the equation.

$h(x)=x^2+2x-1=f(x)+x+1$
$h(x)=0\Rightarrow f(x)=-x-1$

Draw the line $y=-x-1$ and the x-coordinates of the intersection points are the solutions of the equation.

3. Great, thanks for your help