For a given parabola y2=4ax, two variable chords PQ and RS at right angles are drawn through the fixed point A(x1, y1) inside the parabola, making variable angles θ and α with x-axis. If r1, r2, r3, r4 are distances of P, Q, R and S from A, then the value of 1r1r2+1r3r4

For a given parabola y2=4ax, two variable chords PQ and RS at right an

1.	For a given parabola y2=4ax, two variable chords PQ and RS at right angles are drawn through the fixed point A(x1, y1) inside the parabola, making variable angles θ and α with x-axis. If r1, r2, r3, r4 are distances of P, Q, R and S from A, then the value of 1r1r2+1r3r4
Answer» For a given parabola $y^{2} = 4 a x$ , two variable chords PQ and RS at right angles are drawn through the fixed point $A (x_{1}, y_{1})$ inside the parabola, making variable angles $θ$ and $α$ with x-axis. If $r_{1}, r_{2}, r_{3}, r_{4}$ are distances of P, Q, R and S from A, then the value of $\frac{1}{r_{1} r_{2}} + \frac{1}{r_{3} r_{4}}$