Mathematics for IGCSE & O level - Algebraic Manipulation (Section 5 - No. 12)
For the expression x² + bx + c, if 'c' is negative, which is true about the factors?
Both factors are positive.
Both factors are negative.
One factor is positive and one is negative.
The factors have the same sign as 'b'.
解释
If 'c' is negative, the factors must have opposite signs.