The directrix x=-7 must be perpendicular to the axis that goes through the focus (7,0), then the axis of this parabola is y=0
The directrix cuts the axis of the parabola at the point (-7,0)
The vertex of the parabola V=(h,k) is the midpoint of the points (-7,0) and (7,0=
h=(-7+7)/2=(0)/2→h=0
k=(0+0)/2=(0)/2→k=0
Vertex: V=(h,k)→V=(0,0)
As the axis of the parabola is horizontal, the parabola has an equation of the form:
(y-k)^2=4p(x-h)
The parabola opens to the right then p is positive (p>0)
p is the distance between the vertex and the focus, the p=7
(y-k)^2=4p(x-h)
(y-0)^2=4(7)(x-0)
y^2=28x
Answer: <span>The equation of the parabola whose focus is at (7, 0) and directrix at x = -7 is: y^2=28x</span>
1. 19.6
2. 30.4
3. 0.486
4. 56.4
5. 90.2
6. 54
7. 1.19
8. 212
Answer:
(b)
Step-by-step explanation:
Given
Required
The graph
First, make y the subject
Divide through by 3
Let x = 3
Let x = 6
So, we plot the graph through
and
See attachment for graph
Answer:
C
Step-by-step explanation:
Male Female Total
Income over $50,000 485 385 870
Income below $50,000 65 65 130
<span>Total 550 450 1,000
Probability of being male: 550/1000 = 0.55
Probability of earning over $50,000: 870/1000 = 0.87
0.55 x 0.87 = 0.4785
Probability of being male and earning over $50,000: 485/550 = 0.8818
</span><span>C) No, P(being male | the person earns over $50,000) ≠ P(being male)</span><span>
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