Question

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

Answer 1

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.

Answer 2

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`