Question 120476
{{{x^2+9=0}}}
Get the x^2 term alone:
{{{x^2=-9}}}
Take the square root of both sides:
{{{sqrt(x^2)=sqrt(-9)}}}
Notice now you have to take the square root of a negative number of the right side. You can re-write this as:
{{{x=sqrt(-1*9)}}}
{{{x=sqrt(-1)*sqrt(9)}}}
Note that i is defined as follows:
{{{i=sqrt(-1)}}}
So you can rewrite it as:
{{{x=i*sqrt(9)}}}
the square root of 9 is +/-3. So your final answer is:
x=+/-3i
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Good Luck,
tutor_paul@yahoo.com