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### IB Distance between two points

Posted: Tue Apr 23, 2013 4:17 am
IB Mathematical Studies, Coordinate geometry

How can we find the parameter c if these A(4,c) and B(-2,3) are 6 units apart?

Thanks

### Re: IB Distance between two points

Posted: Tue Apr 23, 2013 4:25 am
IB Maths Studies, Coordinate geometry, Distance Formula

The distance between two points $A(x_{1}, y_{1})$ and
$B(x_{2}, y_{2})$ is given by the following formula:

$d_{AB}= \sqrt{( x_{2}- x_{1})^2+( y_{2}- y_{1})^2}$

Applying the Distance formula in your case we have
$d_{AB}= \sqrt{(-2-4)^2+(3-c)^2}=\sqrt{36+(3-c)^2}=6 \rightarrow$

$\rightarrow ( \sqrt{36+(3-c)^2})^2=6^2 \rightarrow$ (by squaring both sides)

$\rightarrow (36+(3-c)^2)=36 => (3-c)^2=0 \rightarrow 3-c=0$

$\rightarrow c=3$

### Re: IB Distance between two points

Posted: Tue Apr 23, 2013 4:27 am
Thanks Nicole!