
Patrick B. answered 10/12/19
Math and computer tutor/teacher
will prove it by contradiction....
P+Q = 1 is given
Then Q = 1 - P
Assume or Suppose PQ > 1/4.
Then PQ - 1/4 > 0.
P(1-P) - 1/4 > 0
P - P^2 - 1/4 > 0
P^2 - P + 1/4 < 0
4P^2 - 4P + 1 < 0
(2P - 1)(2P -1) < 0
(2P - 1)^2 < 0
this is a contradiction... the square of anything must be positive or zero