the complete question is
Point A has an x coordinate of −2 and lies in a circle with a center at (0, 0) and a radius of 5.
To the nearest tenth, what is the y-coordinate for point A?
A: 4.5
B: 4.6
C: 4.7
D: 4.8
see the attached figure
we know that
the equation of the circle is
(x-h)²+(y-k)²=r²
(h,k) is the center---------> (h,k) is the point (0,0)
r=5 units
so
(x-h)²+(y-k)²=r²--------> (x-0)²+(y-0)²=5²------> x²+y²=25
substitute the value of x=-2 in the equation
(-2)²+y²=25------> y²=25-4------> y=(+/-)√21
the y coordinate of point A is positive----> see the picture
therefore
y=√21-----> 4.58-----> y=4.6
the answer is
the y-coordinate for point A is 4.6
