1. ACT Stuff

Which of the following points lies on the perimeter of the circle given by the equation (x-2)squared+ (y+5)squared = 16?
A. (2,-5)
B. (2,-1)
C. (-2,5)
D. (-2,1)
E. (square root of 2, square root of 5)

How do i even go about finding out the options? -confuzzled-

2. $(x-2)^2 + (y+5)^2 = 16$

Each of the options are coordinates of the form $(x, y)$. So simply plug in the values of each coordinate pair to determine whether or not the above equation is satisfied. For example, looking at A. (2, -5), we have:
$(2 -2)^2 + ((-5)+5)^2 = 0 + 0 = 0 \neq 16$

So A cannot be the right answer.

3. Originally Posted by o_O
$(x-2)^2 + (y+5)^2 = 16$

Each of the options are coordinates of the form $(x, y)$. So simply plug in the values of each coordinate pair to determine whether or not the above equation is satisfied. For example, looking at A. (2, -5), we have:
$(2 -2)^2 + ((-5)+5)^2 = 0 + 0 = 0 \neq 16$

So A cannot be the right answer.
Your awesome. And i am ashamed of how stupid i felt after you explained that :x