CHAPTER 4
QUADRATIC EQUATIONS
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| 1. | Standard form of a Quadratic Equation is ax² + bx + c = 0, a ≠ 0 |
| 2. | Examples of Quadratic Equations: x² − 6x + 4 = 0 2x² − 7x = 0 |
| 3. | Examples of equations which are not quadratic: x + 3/x = x² x² + 2√x − 3 = 0 |
| 4. | A real number α is a root of the quadratic equation ax² + bx + c = 0 if aα² + bα + c = 0 |
| 5. | Zeros of the quadratic polynomial ax² + bx + c are the same as the roots of the quadratic equation ax² + bx + c = 0 |
| 6. | Factorisation Method: If ax² + bx + c = 0 can be factorised into two linear factors, then equate each factor to 0 to find the roots. |
| 7. | Formula Method: The real roots of ax² + bx + c = 0 are given by: (−b ± √(b² − 4ac)) / 2a |
| 8. | Nature of the roots depends on the discriminant D = b² − 4ac |
| 9. | For the quadratic equation ax² + bx + c = 0: (i) (ii) (iii) |