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Find the coordinate of the focus, axis of the parabola, the equation of the directrix and the length of the latus rectum.1. y2 = 20x2. x2 = 83. 3x2 = -15 |
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Answer» 1. Comparing the equation with the general form we get; 4a = 20 ⇒ a = 5 Coordinate of focus are (5, 0) Axis of the parabola is y = 0 Equation of the directrix is x = -5 Length of latus rectum = 4 × 5 = 20. 2. Comparing the equation with the general form we get; 4a = 8 ⇒ a = 2 Coordinate of focus are (0, 2) Axis of the parabola is x = 0 Equation of the directrix is y = – 2 Length of latus rectum = 4 × 2 = 8. 3. Convert the equation into general form, we get x2 = -5y. Comparing the equation with the general form we get; 4a = 5 ⇒ a = \(\frac{5}{4}\) Coordinate of focus are (0, −\(\frac{5}{4}\)) Axis of the parabola is x = 0 Equation of the directrix is y = \(\frac{5}{4}\) Length of latus rectum = \(\frac{4 \times 5}{4}\) = 5. |
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