Identify the cylinder with the smallest surface area

At 2:00 PM a car's speedometer reads 30 mi/h. At 2:10 PM it reads 50 mi/h. Show that at some time between 2:00 and 2:10 the acce

Daniel [21]

Answer: If we define 2:00pm as our 0 in time; then:

at t= 0. the velocity is 30 mi/h.

then at t = 10m (or 1/6 hours) the velocity is 50mi/h

Then, if we think in the "mean acceleration" as the slope between the two velocities, we can find the slope as:

a= (y2 - y1)/(x2 - x1) = (50 mi/h - 30 mi/h)/(1/6h - 0h) = 20*6mi/(h*h) = 120mi/ $h^{2}$

Now, this is the slope of the mean acceleration between t= 0h and t = 1/6h, then we can use the mean value theorem; who says that if F is a differentiable function on the interval (a,b), then exist at least one point c between a and b where F'(c) = (F(b) - F(a))/(b - a)

So if v is differentiable, then there is a time T between 0h and 1/6h where v(T) = 120mi/ $h^{2}$

5 0

3 years ago

Is x=12 a solution to the given inequality x > 5

Ludmilka [50]

Answer: True

Step-by-step explanation:

Substitute 12 for x in the inequality

x > 5

12 > 5

12 is greater than 5 so x = 12 is a solution to x > 5

4 0

2 years ago

Find the smallest relation containing the relation {(1, 2), (1, 4), (3, 3), (4, 1)} that is:

professor190 [17]

Answer:

Remember, if B is a set, R is a relation in B and a is related with b (aRb or (a,b))

1. R is reflexive if for each element a∈B, aRa.

2. R is symmetric if satisfies that if aRb then bRa.

3. R is transitive if satisfies that if aRb and bRc then aRc.

Then, our set B is $\{1,2,3,4\}$ .

a) We need to find a relation R reflexive and transitive that contain the relation $R1=\{(1, 2), (1, 4), (3, 3), (4, 1)\}$

Then, we need:

1. That 1R1, 2R2, 3R3, 4R4 to the relation be reflexive and,

2. Observe that

1R4 and 4R1, then 1 must be related with itself.
4R1 and 1R4, then 4 must be related with itself.
4R1 and 1R2, then 4 must be related with 2.

Therefore $\{(1,1),(2,2),(3,3),(4,4),(1,2),(1,4),(4,1),(4,2)\}$ is the smallest relation containing the relation R1.

b) We need a new relation symmetric and transitive, then

since 1R2, then 2 must be related with 1.
since 1R4, 4 must be related with 1.

and the analysis for be transitive is the same that we did in a).

Observe that

1R2 and 2R1, then 1 must be related with itself.
4R1 and 1R4, then 4 must be related with itself.
2R1 and 1R4, then 2 must be related with 4.
4R1 and 1R2, then 4 must be related with 2.
2R4 and 4R2, then 2 must be related with itself

Therefore, the smallest relation containing R1 that is symmetric and transitive is

$\{(1,1),(2,2),(3,3),(4,4),(1,2),(1,4),(2,1),(2,4),(3,3),(4,1),(4,2),(4,4)\}$

c) We need a new relation reflexive, symmetric and transitive containing R1.

For be reflexive

1 must be related with 1,

2 must be related with 2,

3 must be related with 3,

4 must be related with 4

For be symmetric

since 1R2, 2 must be related with 1,
since 1R4, 4 must be related with 1.

For be transitive

Since 4R1 and 1R2, 4 must be related with 2,
since 2R1 and 1R4, 2 must be related with 4.

Then, the smallest relation reflexive, symmetric and transitive containing R1 is

$\{(1,1),(2,2),(3,3),(4,4),(1,2),(1,4),(2,1),(2,4),(3,3),(4,1),(4,2),(4,4)\}$

5 0

2 years ago

(24xy^3-16x^2y^2+32x^2y)/8xy

Ahat [919]

(24xy^3-16x^2y^2+32x^2y)/8xy

(‌24xy^3−16x^2y^2+32x^2y8‌x)(y) =−2x^3y^3+3x^2y^4+4x^3y^2

4 0

3 years ago

Svana wants to solve the equation x - 1.0675 = 3x - 4145.

AysviL [449]

Answer: D

Step-by-step explanation:

Given that Svana wants to solve the equation 1/2x - 1.0675 = 3x - 4145.

This equation is a system of equations which can be solved by using simultaneous equation methods.

But if she uses a graphing program to graph the equations y = 1/2x - 1.0675 and y = 3x - 4.145

The solution of 1/2x - 1.0675 = 3x - 4.145. Will be the point of intersection of the two equation.

Trace the point of intersection to the x - axis and also to the y - axis.

The solution to the system of equations is ( 1.231, - 0.452 )

3 0

3 years ago

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