Algebrahard · Past Paper

If a and c have opposite signs, then the roots of ax^2 + bx + c = 0 are:

AAlways real
BAlways imaginary
CReal and equal
DIrrational only

✓ Correct Answer: AAlways real

If a and c have opposite signs, ac is negative, so -4ac is positive. Thus b^2 - 4ac > 0, ensuring real roots.

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