The value of √4 is:

Given:
√4 = ? 

Concept Used: ​

the radical symbol √ is defined to give the principal (non-negative) square root.
By convention, The equation  x² = 4 has two solutions,  x = $$\pm 2$$​ 
Solution:
Factor the number: 4 = 2$$\times$$​2

So, 

$$\sqrt4 =\sqrt{2\times 2}$$​ = $$2$$​​
 As a result, the value of 4 is 2