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dybincka [34]
3 years ago
5

Calculator question.

Mathematics
1 answer:
alexgriva [62]3 years ago
3 0

Answer:

D. [0,pi/2]

Step-by-step explanation:

when Ф = 0 in radian

r²=  4cos (2(0))

r² = 4 * 1

r² = 4

∴ r = √4 = 2

r = 2.

when Ф = π/2 in radian

r²=  4cos (2(π/2))

r² = 4 * -1

r² = -4

∴ r = 0

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djverab [1.8K]

Answer: 1726

Step-by-step explanation:

A=2(wl+hl+hw)

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4 0
3 years ago
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A certain virus infects one in every 400 people. A test used to detect the virus in a person is positive 90% of the time if the
Ahat [919]

Answer:Given:

P(A)=1/400

P(B|A)=9/10

P(B|~A)=1/10

By the law of complements,

P(~A)=1-P(A)=399/400

By the law of total probability,

P(B)=P(B|A)*P(A)+P(B|A)*P(~A)

=(9/10)*(1/400)+(1/10)*(399/400)

=51/500

Note: get used to working in fraction when doing probability.

(a) Find P(A|B):

By Baye's Theorem,

P(A|B)

=P(B|A)*P(A)/P(B)

=(9/10)*(1/400)/(51/500)

=3/136

(b) Find P(~A|~B)

We know that

P(~A)=1-P(A)=399/400

P(~B)=1-P(B)=133/136

P(A∩B)

=P(B|A)*P(A) [def. of cond. prob.]

=9/10*(1/400)

=9/4000

P(A∪B)

=P(A)+P(B)-P(A∩B)

=1/400+51/500-9/4000

=409/4000

P(~A|~B)

=P(~A∩~B)/P(~B)

=P(~A∪B)/P(~B)

=(1-P(A∪B)/(1-P(B)) [ law of complements ]

=(3591/4000) ÷ (449/500)

=3591/3592

The results can be easily verified using a contingency table for a random sample of 4000 persons (assuming outcomes correspond exactly to probability):

===....B...~B...TOT

..A . 9 . . 1 . . 10

.~A .399 .3591 . 3990

Tot .408 .3592 . 4000

So P(A|B)=9/408=3/136

P(~A|~B)=3591/3592

As before.

Step-by-step explanation: its were the answer is

5 0
3 years ago
Can someone please help me with math.
Inessa05 [86]

4- 20

I created an equation for this one:

4x+x=100

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  • x= the number
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5x=100

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x=20

5. One pretzel costs $3

Create an equation:

  • 2s+p=7
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Mulitply 2s+p=7 by -2 so you can use elimination.

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8 0
2 years ago
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My son, Garrett, is 11 years old and has a piggy bank that he wants to fill. He started with 5 one dollar bills. Every Saturday
Debora [2.8K]

Answer:

1) M(x) = 5 + 3x

2) Dependent variable; 3 dollar bills

Independent variable: chores

3) Range is continuous

Domain is discrete

4) Range: 0 ≤ x ≤ 10

Domain: 5 ≤ M ≤ 35

Step-by-step explanation:

We are told he started with 5 number of $1 dollar bills and that every Saturday, he earns 3 more $1 dollar bill.

Thus, total number of $1 bills earned after x number of Saturdays(weekly) is;

M(x) = 5 + 3x

After 10 weeks, total number is;

M(10) = 5 + 3(10)

M(10) = 35

The dependent variable is the 3 more dollar bills earned each Saturday because it depends on chores he completed. While the independent variable is the chores because it doesn't depend on anything.

After 10 weeks, the range and domain will be;

Range: 0 ≤ x ≤ 10

For the; Domain:

For x = 1, M(0) = 5 + 3(0) = 5

M(10) = 35

Thus;

Domain: 5 ≤ M ≤ 35

The range could be all numbers in the interval from 0 to 10. Thus, it is continuous.

Whereas, the domain doesn't contain all the numbers in the interval from 5 to 35. Thus it is Discrete.

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3 years ago
Find the vertex of the quadratic function: y= 2x^2 - 12x + 9
masha68 [24]

Answer:

6+_3√2/2

Step-by-step explanation:

y=2x²-12x+9

y=6+3√2/2

4 0
3 years ago
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