Variable straight lines \(y=m x+c\) make intercepts on the curve \(y^2-4 a x=0\) which subtend a right angle…
- \((4 a, 0)\)
- \((2 a, 0)\)
- \((-4 a, 0)\)
- \((-2 a, 0)\)
Solution

\(\begin{aligned} \Rightarrow \quad y^2-4 a x\left(\frac{y-m x}{c}\right) & =0 \\ c+4 a m & =0 \quad \ldots (i) \end{aligned}\) On putting the value of ' \(c\) ' in the line, we get \(y=m(x-4 a)\), represent family of line passes through \((4 a, 0)\). Hence, option (1) is correct.
Asked in: AP EAMCET 2019 (20 Apr Shift 1)