Answer:
A
Step-by-step explanation:
For any point (x, y ) on the parabola the focus and directrix are equidistant
Using the distance formula
= | y - 8 |
Squaring both sides gives
(x - 2)² + (y - 4)² = (y - 8)²
(x - 2)² + y² - 8y + 16 = y² - 16y + 64 ( rearrange and simplify )
(x - 2)² = - 8y + 48
8y = - (x - 2)² + 48
y = - (x - 2)² + 6 → A
Answer:
Dimensions of the rug = 13 ft × 26 ft
Step-by-step explanation:
Dimensions of the room = 21 ft × 34 ft
Area of the room = 21 × 34 = 714 ft²
Cynthia wants to leave a uniform strip of floor around the rug.
Let the width of the rug = x ft
Then the dimensions of the rug will be = (21- 2x)ft × (34 - 2x)ft
Area of the rug = (21 - 2x)×(34 - 2x) square feet
338 = (21 - 2x)×(34 - 2x)
338 = 714 - 68x - 42x + 4x²
4x² - 110x + 714 - 338 = 0
4x² - 110x + 376 = 0
2x² - 55x + 188 = 0
2x² - 47x - 8x + 188 = 0
x(2x - 47) - 8(x - 47) = 0
(x - 4)(2x - 47) = 0
x = 4,
For x = 23.5 area of the rug will be negative.
Therefore, x = 4 ft will be the width of the rug.
Dimensions of the rug will be 13 ft × 26 ft.