SOLUTION: Equation of a Circle 11.a) State the radius of the circle given by the equation x^2+y^2=169 Thank you sooooo much!!!!

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Equation of a Circle 11.a) State the radius of the circle given by the equation x^2+y^2=169 Thank you sooooo much!!!!      Log On


   

Question 189843: Equation of a Circle
11.a) State the radius of the circle given by the equation x^2+y^2=169
Thank you sooooo much!!!!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2%2By%5E2=169 Start with the given equation


x%5E2%2By%5E2=13%5E2 Rewrite 169 as 13%5E2


%28x-0%29%5E2%2B%28y-0%29%5E2=13%5E2 Rewrite x%5E2 as %28x-0%29%5E2 and y%5E2 as %28y-0%29%5E2


Notice how the last equation is of the form %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2 (which is the general equation of a circle) where (h,k) is the center and "r" is the radius.

In this case, h=0, k=0 and r=13. So this is a circle centered at (0,0) with a radius of 13 units