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2 years ago

Question 7

Mathematics

1 answer:

Ksenya-84 [330]2 years ago

3 0

Answer:

(4,2) and (2,-2)

Step-by-step explanation:

using m=y2-y1/x2-x1

m= -2-2/2-4=-4/-2

therefore,

m=2

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I would like some help

Anettt [7]

Answer:

Step-by-step explanation:

5 0

2 years ago

b) If parametric equations of a flow line are x = x(t), y = y(t), explain why these functions satisfy the differential equations

sineoko [7]

Answer:

The equation of the the flow line that passes through the point (x, y) = (−1, −1) is

In y + In x = 0 or in another form, xy = 1.

Step-by-step explanation:

The pathline equation for a vector field is given by F(x,y) = xî - yj

The velocity vector field for the streamline of the flow is given by

V(x, y) = (dx/dt)î + (dy/dt)j

From the question, it is given that

(dx/dt) = x

(dy/dt) = -y

Hence, the velocity vector field for the streamline of the flow in question is

V(x, y) = xî - yj

which coincides with the pathline vector field of the flow.

The only time the pathline and streamline vector field coincide and have the same equation is when the flow is a steady state flow.

That is, the properties of the fluid flowing isn't changing with time!

Hence, this flow is a steady state flow!

We're told to solve the differential equation.

(dx/dt) = x

(dy/dt) = -y

but

(dy/dx) = (dy/dt) × (dt/dx)

(dy/dx) = -y/x

(dy/y) = -(dx/x)

∫(dy/y) = -∫ (dx/x)

In y = - In x + c

where c is the constant of integration

In y + In x = c

In (xy) = c

Inserting the values of (x, y) given in the question,

In (-1 × -1) = c

In 1 = c

0 = c

c = 0

In y + In x = 0

In (yx) = 0

xy = e⁰ = 1

xy = 1

So, the equation of the the flow line that passes through the point (x, y) = (−1, −1) is

In y + In x = 0 or in another form, xy = 1

Hope this Helps!!!

4 0

3 years ago

Bad gums may mean a bad heart. Researchers discovered that 80% of people who have su ered a heart attack had periodontal disease

saul85 [17]

Answer:

0.069 = 6.9% probability that he or she will have a heart attack

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Does not have periodontal disease

Event B: Has a heart attack.

Probability of not having a periodontal disease:

100 - 80 = 20% of 10%(had a heart attack).

30% of 100-10 = 90%(did not have a heart attack). So

$P(A) = 0.2*0.1 + 0.3*0.9 = 0.29$

Intersection of A and B:

Not having the disease, suffering a heart attack, so 20% of 10%.

$P(A cap B) = 0.2*0.1 = 0.02$

What is the probability that he or she will have a heart attack?

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.02}{0.29} = 0.069$

0.069 = 6.9% probability that he or she will have a heart attack

6 0

3 years ago

If a determinant of a 2 x 2 matrix is 0, what can you conclude about the inverse of the matrix?

icang [17]

Any singular matrix (a matrix with zero determinant) has no inverse.

3 0

2 years ago

(x+3)^2 = x^2-3(1-x)

Oxana [17]

(x+3)(x+3) = x^2 -3 + 3x
x^2 + 3x + 3x + 9 = x^2 + 3x - 3
x^2 + 6x + 9 = x^2 + 3x - 3
6x + 9 = 3x - 3
3x + 9 = -3
3x = -12
x = -4

Check:
(-4+3)^2 = (-4)^2 - 3(1+4)
(-1)^2 = 16 - 3(5)
1 = 16-15
1 = 1 :)

7 0

2 years ago