Question

I don't understand how to complete the square for x^2+3x+4 because 3x is an odd number, surely you could not put 1.5 in the square?

Answer 1

write it as x^2+2*3/2x+ (3/2)^2 - (3/2)^2+ 4
(x^2+2*3/2x+ (3/2)^2 )- (3/2)^2+ 4
(x+3/2)^2 +(4-9/4)
so you need to add (16-9)/4= 7/4

Answer 2

or add x to the question it becomes (x+2)^2

Answer 3

i understand the first bit but surely you can only have integers within the square?