Question

1. Centre of a circle Q is on the Y-axis. The circle passes through the points (0,7) and
(0, -1). If it intersects the positive X-axis at (p, 0), what is the value of 'p"?​

Answer 1

Answer:

p=±√7

Step-by-step explanation:

Let the centre O is (0,y)

This passes through A(0,7) and B (0,-1)

so r²=OA²=OB²

0+(y-7)²=0+(y+1)²

y²-14y+49=y²+2y+1

16y=48

y=3

Thus center is O (0,3)

r²=OA²=0+(3-7)²

r2=16

r=4

circle intersects the positive X-axis at P (p, 0)

So OP²=r²

(p-0)²+(3-0)²=16

p²+9=16

p²=7

p=±√7