Re: maths questions help
1. The line with equation y = mx is tangent to the circle with centre (10,0) and radius 5 at the point P(x,y)
a. find the equation of the circle
b. show that the x-coordinate of the point P satisfies the equation (1+m^2)x^2 - 20x + 75=0
c. use the discriminant for this...