Answer:
15.62
Step-by-step explanation:
The length XY is found from the distance formula:
d = √((x2 -x1)² +(y2 -y1)²)
d = √((4 -(-8))² +(-6 -4)²) = √(12² +(-10)²) = √244
d ≈ 15.62 . . . units
The length of XY is approximately 15.62 units.
This seems disgusting to solve directly, so let's convert this to vertex form.
1) Divide all terms by 1/2:
2y = -x² - 4x + 14
2) Complete the square:
2y = -(x² + 4x - 14)
2y = -(x² + 4x + 4 - 4 - 14)
2y = -[(x + 2)² - 18]
2y = -(x + 2)² + 18
3) Rewrite in vertex form:
(x + 2)² = -2y + 18
(x + 2)² = -2(y - 9)
Now, we know the vertex is at (-2, 9)
It's a concave down parabola
The axis of symmetry is simply the x-ordinate of the vertex.
The focus is at (-2, 17/2)
The directrix is at (-2, 19/2)
The y-intercept is at y = 7
Answer:
step 1. <2 + 40° = <1
step 2. <1 + 72° = 180°
step 3. <1 = 108°
step 4. <2 = 108° - 40° = 68°.
Answer:
19.193 million
Step-by-step explanation:
Put the given value in the formula and do the arithmetic.
P(220) = 19.71/(1 +61.22e^(-0.03513·220))
P(220) = 19.71/(1 +61.22e^-7.7286) = 19.71/(1 +0.02694046)
P(220) ≈ 19.193 . . . million
