(a+b)2= ?

Year: 1964 Summer vacation time.

After the vacation I was to take composite maths as my elective and learn algebra, geometry, etc.

My elder brother's friend Narayanan was a genius in mathematics having set a university record by scoring centum in all the subjects in his B.Sc. exams.

My father asked me not to waste my vacation. He suggested that I go to Narayanan and learn algebra. He was living with his parents in Greams Road Police quarters and I used to cycle down to his house. Both of us used to sit in Modas and with notebook and pencil in hand he used to teach me algebra. What a pleasure it was to learn from him!

When school classes began after vacation, we got two new teachers for mathematics. They were very good in their subject. We were about sixty students in two classes with composite maths as our electives.

In the first quarterly exam the question (p+q)2 = ? was answered correctly only be three students including me.

The teacher asked: Why? What happened?

Many students stood up and said: Sir, you only taught us (a+b)2=a2 +b2+2ab and

(x+y)2=x2+y2+2xy, but you never taught us (p+q)2 = !!!!!!