A circle of radius 3 is centered at the origin and passes through the point .(2,sqrt5)
(a) Find an equation for the line through the origin and the point .

(b) Find an equation for the tangent line to the circle at . (2,sqrt5)

Question

A circle of radius 3 is centered at the origin and passes through the point .(2,sqrt5)
(a) Find an equation for the line through the origin and the point . 
 

(b) Find an equation for the tangent line to the circle at . (2,sqrt5)

anonymous · Answer

1) Find the slope line going through $(0, 0)$ and $(2,\sqrt{5})$
2) The slope of a perpendicular line is just the negative reciprocal.

anonymous · Answer

once you have the slopes of each you can use point slope formula

anonymous · Answer

if it is centered at the origin and has radius 3, then the equation must be $x^2+y^2=9$

anonymous · Answer

if you can use calculus, this is easy
if not you do what @wio  said

anonymous · Answer

actually @wio  answer is easiest nvm