The number of solutions is not "at least" two. There is always two OR ONE solutions, but they may not be real numbers. The solutions may contain a term multiplied by the square root of a negative number, which is "imaginary".
The reason for two solutions can be seen by looking at the "quadratic formula" for solutions:
(1/2a)[-b +/- sqrt(b^2 - 4ac)]
The two soltions are a result of the +/- term. When b^2 - 4ac equals zero, there is only one solution.
a,b and c are the coefficients in the standard form of a quadratic equation,
ax^2 + bx + c = 0
Why are there always at least two solutions in quadratic equations?
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