Estimate to the nearest integer.

Question

Square root of -55

Answer 1

7*7=49
8*8=64
7.5*7.5=56.25
So
sqrt(55)=7.5 approx.

To get a better estimate,
calculate (mentallY)
7.5-(55-56.25)/(2*7.5)
=7.5-1.25/15
=7.5-1/12
=7.417

Answer 2

3√7.5