The reflecting dish of a parabolic microphone has a cross-section in the shape of a parabola. the microphone itself is placed on the focus of the parabola. if the parabola is 24 inches wide and 9 inches deep, how far from the vertex should the microphone be placed?
let the parabola have the form y^2 = 4px, where (p,0) is the focus
the point (9,12) would lie on this curve, so
144 = 4p(9)
4p = 144/9 = 16
p = 4 , focus is (4,0)
So the microphone should be placed 4 inches from the vertex.
1. B. ellipse
Domain: {–4 ≤ x ≤ 4}
Range: {–3 ≤ y ≤ 3}
2. B. y= x²/4
3. D. y = 1/6x²
4. D. 4 inches
5. D. x = 1/12(y – 4)2 + 2
6. B. (x – 4)² + (y – 5)² = 49
7. (x + 7)² + (y + 2)² = 25
8.D. (x + 3)² + (y + 2)² = 9
9. B. Center at (5,-3); radius: 5
10. D. x²/23 + y²/144 = 1
11. A. (0, ±6)
12. C. 10 feet
13. A. (6,0) and (-6,0)
14. A. (0, ± 5)
1.B
2.B
3.D
4.D
5.C
6.A
7.A
8.D
9.B
10.D
11.A
12.D
13.A
14.A
100/100
Just be careful because for math they are different in most test
please be careful with only letter answers! they give different equations during quizzes!!
So are these the right answers or no
are you dumb they just said the test are different
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dont trust only letter answers. if you see a written out answer that has the same question number on your test, and matches an available answer to that question, it's the correct one. for answers you dont get from here, just look up the questions individually
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Answers to 5.7.1 - Test - PConnexus
1. C, Ellipse
2. D, graph
3. B, y=1/4 x^2
4. C, 9in
5. D, x=1/12(y-4)^2+2
6. D, (x-2)^2 + (y-4)^2 =25
7. B,
8. C
9. A
10. B
11. A
12. C
13. C, graph
14. D, (0,+5)
^^left some out. Figured by #7 you would know if it was the right test or not
I wish yall had the same test as me
I'm sorry about that, the answers can vary between tests or exams depending on who is administering them. It's important to review the material thoroughly and understand the concepts in order to perform well on any math exam.
Quadratic Relations and Conic Sections Unit Test Part 1
1. B. Ellipse
Domain:{ -4<=y<=4}
Range:{-3<=y<=3}
2. C. y= x^2/3
3. C. y=1/10x^2
4. D. 4 inches
5. D. x= 1/12 (y-4)^2+2
6. D. (x-2)^2+(y-4)^2=25
7. C. (x+6)^2+(y+3)^2=25
8. D. (x+3)^2+(y+2)^2=9
9. A. center at (7,-6); radius 4
10. B. x^2/25+y^2/169=1
11. C. (0,=+3)
12. C. 10 feet
13. C. (the graph description: the left parabola opens left. the right parabola opens right)(the center point of each parabola is left- (-3,0) right-(3,0)
14. D. (0,=+5)