TS EAMCET 5 May 2018 Shift 2 Solved Paper

The equation of normal to parabola y2=4ax at (at2,2at) is,
y+tx=2at+at3
Consider the figure shown below.
Therefore,
y2=4ax(

y+tx

2at+at3

)
y2(2at+at3)=4ax(y+tx)
4atx2+4axy−(2at+at3) y2=0
since OP and OQ are at right angles, then the sum of coefficient of x2 and y2 is equal to zero.
4at−2at−at3=0
t2=2
t=±√2
Therefore,
y=±√2x
Hence, the slope of normal is ±√2.