Radical Expressions in Algebra.

Take an equation:

-a^2+2

It's easy enough to start solving for a:

-a^2=-2

Now I am aware that taking the square root at this point would mean I would have to start using an imaginary number "i" as it is called. It is my understanding right now that:

a^2=2

is an equivalent equation to -a^2=-2 since both sides of the equation could be divided by negative one?

I've been reviewing my algebra and so when a square root of both sides of an equation takes place I have to use a +- (plus-minus) sign?

Is that really true in all cases?

Thanks in advance...

Re: Radical Expressions in Algebra.

Quote:

Originally Posted by

**sepoto** Take an equation:

-a^2+2

That's not an equation; you mean this: -a^2 + 2 = 0

Really, all it is is some cruel math teacher changed a^2 - 2 = 0 !