Semi-latus rectum is the harmonic mean of SP and SQ where P and Q are the extrimities of the focal chord

If l denotes the semi-latus rectum of the parabola y^2= 4ax and SP and SQ denote the segments of any focal chord PQ, S being the focus, then SP, l and SQ are in the relation :

Prove that the semi-latus rectum of the parabola y^2 = 4ax is the harmonic mean between the segments of any focal chord of the parabola.

Prove that the semi-latus rectum of the parabola 'y^2 = 4ax' is the harmonic mean between the segments of any focal chord of the parabola.

Prove that the semi-latus rectum of the parabola y^(2) = 4ax is the harmonic mean between the segments of any focal chord of the parabola.

Prove that the semi-latus rectum of the parabola y^(2) = 4ax is the harmonic mean between the segments of any focal chord of the parabola.

Prove that the semi-latus rectum of the parabola y^(2) = 4ax is the harmonic mean between the segments of any focal chord of the parabola.

If l denotes the semi-latusrectum of the parabola y^(2)=4ax, and SP and SQ denote the segments of and focal chord PQ, being the focusm the SP, I, SQ are in the relation

If l denotes the semi-latusrectum of the parabola y^(2)=4ax, and SP and SQ denote the segments of and focal chord PQ, S being the focus then SP, I, SQ are in the relation

If H is the harmonic mean of P and Q, then the value of H/(P)+H/(Q) is