the points A and B lie on a circle with centre P, as shown in figure 3.

the point A has coordinates (1,-2) and the midpoint M of AB has coordinates (3,1).

The line l passes through the points M and P.

a)find an equation for l.

Given that the x-coordinate of P is 6,

b) use your answer to part (a) to show that the y-coordinate of P is -1

(i could do this bit if i had the equation)

c) find an equation for the circle