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Now i was taught that when you have an equation such as x^2=9 and you take the sqrt bs of this equation sqrt(x^2)=sqrt(p) you get |x|=3. I was also told that sqrt only returns a positive(non-negative) value. I asked a friend but he was too busy to finish explaining and i just got even more confused. So my question is why do you need the abs value on the x if you know that sqrt is non-negative?
because x can be negative also. whos that friend? he must have told you about this or hes very irresponsible! did he also tell you that x=3 and x=-3 both are solutions to x^2=9 so when we are solving for x (finding the roots) we are looking for both values of x thus we need the absolute value (b/c if not, we have x=sqrt(9)=3, which is only one root)!
thats not what i dont understand! i dont understand how the absolute value gives you both these values?
ok
|-3|=3
and |3|=3
do u agree with that?
if you do, then you would agree
|x|=3 yields x=3 or -3
Oh i see (i think) now i get it now. Thanx a bunch!