Calculate the consumer surplus for the demand function
p = 50 − 4q
when the market price is p = 10.

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.  

its less than 713.21 but greater than 5.2