TS EAMCET 04 May 2019 Shift 1 Solved Paper

The equation of the normal at (4,8) is y=−x+12 so, considerthe diagram,
The X-axis is cut at (12,0)
So, the equation of chord passing through (12,0) and perpendicular to normal is y=x−12
Substitute the value of y in the equation y=16x then,
(12−x)2‌‌=16x
144−24x+x2‌‌=16x
x2−40x+144‌‌=0
(x−36)(x−4)‌‌=0
Simplify the above,
x=4,36
This implies,
y‌‌=4−12
‌‌=−8
And,
y‌‌=36−12
‌‌=24
The length of chord is given by,
√(36−4)2+(24+8)2‌‌=√322+322
‌‌=32√2