The circle x2+y2+4x−7y+12=0 cuts an intercept on y-axis of length

The circle x2+y2+2gx+2fy+c=0 cuts an intercept of length 2f2−c y-axisFor the circle x2+y2+4x−7y+12=0,we haveg=2,f=−7/2 and c=12∴ y-intercept =2f2−c=2494−12=1.