Points A (3,1), B(-1,-11), C(-5,9)

what the slope that passes through A and B

whats the co-ordinates of the midpoint of the line segment AB

whats the equation of the perpendicular bisector of AB

?? show that the line corresponding to the parametric equations

x = t - 14
y = -1/3t
is the same as the perpendicular bisector of AB

what is the equation of the perpendicular bisector of the line segment AC

from the answers of the above find the centre of the circle that passes through a b c

whats the radius of this circle

what the equation of this circle

any help to any of the above would be extremely appreciated

2. Originally Posted by loes
Points A (3,1), B(-1,-11), C(-5,9)

what the slope that passes through A and B
Plug the two points into slope formula.

Originally Posted by loes
whats the co-ordinates of the midpoint of the line segment AB
Plug the two points into the Midpoint Formula.

Originally Posted by loes
whats the equation of the perpendicular bisector of AB
How are perpendicular slopes related? Use this relationship to use the slope found above to find the perpendicular slope.

Then use the midpoint and this slope to find equation of the bisector. It would probably be simplest to start with the point-slope formula.

Originally Posted by loes
?? show that the line corresponding to the parametric equations

x = t - 14
y = -1/3t
is the same as the perpendicular bisector of AB
Solve the first equation for "t=", and plug this into the second equation. Simplify, and compare.

Originally Posted by loes
what is the equation of the perpendicular bisector of the line segment AC
Follow the same procedure as above: find the midpoint, find the slope, find the perpendicular slope, and then find the line equation.

Originally Posted by loes
from the answers of the above find the centre of the circle that passes through a b c
The two line equations form a system of equations. Solve the system to find the intersection point, and thus the center.

Originally Posted by loes
whats the radius of this circle
Plug the center and any of the three given points on the circle into the Distance Formula.

Originally Posted by loes
what the equation of this circle
Plug the center (h, k) and the radius r into the center equation (x - h)^2 + (y - k)^2 = r^2.

If you get stuck, please reply showing how far you have gotten. Thank you!