Hey, got a question, my sis has exams tomorrow and she cant solve this,...its been 7 years ive done this lvl of maths, and dont remember enough to help her...any help ?

Its part of the question

Show A= 1/2(1-x+qx^2)

Given that x can vay, show that Qy=Yr when A is a min and express the min of A in terms of q

First part she did, now 2nd part

I forgot, PQRS is a square