
Stephen K. answered 09/11/14
Tutor
4.9
(798)
Physics PhD experienced in teaching undergraduates
Didi,
You know that if some number, call it x = √2, then x² must be equal to 2, x² = 2. So let's test 1.4.
We multiply and find that 1.4 x 1.4 = 1.96, a little bit less than 2. So no test 1.5, 1.5 x 1.5 = 2.25 which is a bit bigger than 2.
So we can conclude that √2 lies somewhere between 1.4 and 1.5. We might write that this way:
1.4 < √2 < 1.5