Question 541962
The question from my book says that "the radicand of the quadratic formula, {{{ b^2 - 4ac }}}, can be used to determine whether {{{ ax^2 + bx + c = 0 }}} has solutions that are rational, irrational, or not real numbers." 
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I just did this one.
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b^2 - 4ac is the determinant.
If it's a perfect square and >0, there are 2 rational answers or roots.
If it's a perfect square and =0, there are 2 rational answers or roots that are the same.
If it's not a perfect square and >0, there are 2 irrational answers or roots.
If it's <0, there are 2 complex answers or roots.
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I don't know what you mean is "saying the first coefficient is zero", but if it is, if a = 0, then it's a linear equation, bx + c = 0