Co-ordinate geometry question.....

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• Oct 26th 2008, 12:07 PM
cougar
Co-ordinate geometry question.....
Hey im new, stuck on this question :( anyone help me? :D

(A) Find an equation of the line l which passes through the points A(1,0) and B(5,6)?...( I got y = 3/2 x + 3/2)???)

The line m with the equation 2x + 3y = 15 meets l at the point C

(B) Determine the coordinates of C

THe point P lies on m and has x co-ordinate of -3

(c) Show by caclulation PA = PB

Thanks in advanced :D
• Oct 26th 2008, 01:27 PM
Jhevon
Quote:

Originally Posted by cougar
Hey im new, stuck on this question :( anyone help me? :D

(A) Find an equation of the line l which passes through the points A(1,0) and B(5,6)?...( I got y = 3/2 x + 3/2)???)

no, it should be $y = \frac 32x - \frac 32$

Quote:

The line m with the equation 2x + 3y = 15 meets l at the point C

(B) Determine the coordinates of C
just set the lines equal to each other

you have $y = \frac 32x - \frac 32$ and $y = - \frac 23x + 5$

so, $\frac 32x - \frac 32 = - \frac 23x + 5$

now solve for $x$ and then you can solve for $y$ and then you have your point

Quote:

THe point P lies on m and has x co-ordinate of -3

(c) Show by caclulation PA = PB

Thanks in advanced :D
first, find the corresponding y-coordinate for x = -3 on the line m

you can use the distance formula to find the length PA and the length PB and show they are equal to each other.