Thread: quadratic equations?

AT is a tangent at T to a circle, centre O.
OT = x cm AT = (x+5) cm OA = (x+8) cm
a) Show that x^2-6x-39=0
b) Solve the equation x^2-6x-39=0 to find the radius of the circle

Give your answer correct to 3 significant figures.

Someone please help.

Originally Posted by alice

AT is a tangent at T to a circle, centre O.
OT = x cm AT = (x+5) cm OA = (x+8) cm
a) Show that x^2-6x-39=0

I think you probably meant to say: Show that

Originally Posted by alice

b) Solve the equation x^2-6x-39=0 to find the radius of the circle

Give your answer correct to 3 significant figures.

The quadratic will not factor, so use the quadratic formula to solve. Use only the positive root and round to 3 sig digits.

I got