Question
Question: Let PQ and RS be tangents at the extremities of a diameter PR of a circle of radius r. Such that PS ...
Let PQ and RS be tangents at the extremities of a diameter PR of a circle of radius r. Such that PS and RQ intersect at a point X on the circumference of the circle, then 2r equals –
A
PQ.PS
B
2PQ+RS
C
PQ+RS2PQ.RS
D
2PQ2+RS2
Answer
PQ.PS
Explanation
Solution
From the fig. we have
PRPQ = tan (p/2 – q) = cot q
and PRRS = tan q
Ž PRPQ.PRRS = 1
Ž (PR)2 = PQ . PS
Ž (2r)2 = PQ . PS
Ž 2r = PQ.PS.