What is the square root of this equation?

#x^2#=-16

1 Answer
Apr 14, 2017

#x = +-4i#

Explanation:

Given:

#x^2 = -16#

We might say that to solve the equation you should take the square root, which essentially means take the square root of both sides of the equation. The problem with such a statement is that under normal circumstances any non-zero number has two square roots. Those roots may be real or non-real complex roots, but one is minus the other.

In our example we find:

#x = +-4i#

where #i^2 = -1#

That is:

#x = 4i" "# or #" "x = -4i#

So you could say that "the square root of the equation" is the disjunction:

#x = 4i vv x = -4i#

which we abbreviate to:

#x = +-4i#