SOLUTION: What is the equation of the tangent to a circle defined by the equation x^2+y^2-25=0 if the coordinates of the point of tangency are (-4,3)?

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: What is the equation of the tangent to a circle defined by the equation x^2+y^2-25=0 if the coordinates of the point of tangency are (-4,3)?       Log On


   

Question 855249: What is the equation of the tangent to a circle defined by the equation x^2+y^2-25=0 if the coordinates of the point of tangency are (-4,3)?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

x^2+y^2 = 5^2  C(0,0) r = 5

( 0,0)

(-4,3) m = -3/4, slope of the radius drawn

Tangent Line:  m = 4/3

***Using point-slope form, y+-+y%5B1%5D+=+m%28x+-+x%5B1%5D%29 P(-4,3) point of tangency

  y - 3 = 4/3(x + 4)

    y = (4/3)x + 16/3 + 9/3

    y = (4/3)x + 25 /3