Help! Specific Math Question!

<p>In the xy-coordinate plane, circle A is centered at the origin and has a radius of 5. For how many points on circle A i the sum of the x-coordinate squared an the y-coordinate squared greater than 20?</p>

<p>Can someone please thoroughly explain!</p>

<p>Thanks!</p>

<p>An infinite number? Or are you only talking about points with integer coordinates?
If you have a circle in the xy plane with radius 5, and it’s centered at the origin, then the equation of the circle is
x^2 + y^2 = 5^2 = 25.<br>
So all of the points on the circle have x^2 + y^2 > 20.</p>

<p>If you are just talking about points with integer coordinates, then the answer would be 8:
(3, 4), (3, -4), (-3, 4), (-3, -4)
(0, 5), (0, -5), (5, 0), (-5, 0)</p>

<p>OOPS!
Better make that 12!
Overlooked
(4, 3), (4, -3), (-4, 3) and (-4, -3)</p>

<p>@QuantMech Yes it is an Indefinite number. i understand now. Thanks so much =)</p>