Why does #sqrt(49)# have two answers?

2 Answers
Feb 5, 2018

This is because there are two values that can be multiplied by themselves to produce 49 - one positive and the other negative.

Explanation:

This is always the case for a square root. The positive value of a number and the negative value of that same number both yield a positive result when squared.

#7^2 = 49#

#(-7)^2 = (-7)(-7) = 49#

because multiplying two negative values had resulted in a positive result.

Feb 5, 2018

Minus times a minus equals a plus.

Plus times a plus equals a plus

#-7 xx -7 = 49#

#7 xx 7 = 49#

Therefore

#sqrt(49) = -7# or #sqrt(49) = 7#