Question

Ryan’s teacher asked him to graph circle E with equation (x – 5)squared + y squared = 25. Below is the graph he submitted.

What, if anything, did Ryan do wrong when graphing this equation?

Ryan’s graph is accurate.

He graphed a circle with center at (25, 0) instead of at (-5, 0).

He graphed a circle with a radius of 5 instead of a radius of 25.

He graphed a circle with center at (25, 0) instead of at (5, 0).

Answer 1

remember the equation of a circle is \[(x-h)^2 + (y-k)^2 = r^2 \] with the center at (h,k). So where should the center be?

Answer 2

no idea

Answer 3

so if \[(x-h)^2 + (y-k)^2 = r^2\] you can tell that \[r^2 = 25\] from your earlier equation. And you know h is five from the earlier equation, which gives you the x coordinate for the ordered pair for the center. So what do you think k should be?