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OpenStudy (campbell_st):
well they will be complex you are solving an equation... so you need to let
\[x^2 + 9 = 0\]
you need to find the values of x that make the equation zero... and there will be 2 zeros as its a quadratic equation.
subtract 9 from both sides of the equation and then take the square root of both sides.
one solution will be positive and the other negative
hope it helps
OpenStudy (anonymous):
so like x+3 and x-3?
OpenStudy (campbell_st):
not quite... do it step by step...
subtract 9 from both sides of the equation... what do you get?
OpenStudy (anonymous):
x=-9
OpenStudy (anonymous):
well x^2=-9
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OpenStudy (campbell_st):
nearly
\[x^2 = -9\]
now take the square root of both sides..
OpenStudy (anonymous):
it would be x and the sqr root 3 i?
OpenStudy (anonymous):
so is it root 3 i?
OpenStudy (anonymous):
positive and negative
OpenStudy (campbell_st):
well nearly
\[x= \pm \sqrt{-9} ~~~or~~~ x = \pm \sqrt{9i^2}\]
so hopefully this will help you get the answer...
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OpenStudy (anonymous):
sweet thanks
OpenStudy (campbell_st):
you don't need the root since 9 is a square number