7.2×12×0.23 rounded to the nearest hundredths A.19.88 B.19.43 C.19.44 D.19.87

Evaluate the line integral for x^2yds where c is the top hal fo the circle x62 _y^2 = 9

natulia [17]

Parameterize $C$ by

$\mathbf r(t)=\langle x(t),y(t)\rangle=\langle3\cos t,3\sin t\rangle$

where $0\le t\le\pi$ . Then the line integral is

$\displaystyle\int_Cx^2y\,\mathrm dS=\int_{t=0}^{t=\pi}x(t)^2y(t)\left\|\frac{\mathrm d\mathbf r(t)}{\mathrm dt}\right\|\,\mathrm dt$
$=\displaystyle\int_{t=0}^{t=\pi}(3\cos t)^2(3\sin t)\sqrt{(-3\sin t)^2+(3\cos t)^2}\,\mathrm dt$
$=\displaystyle3^4\int_{t=0}^{t=\pi}\cos^2t\sin t\,\mathrm dt$

Take $u=\cos t$ , then

$=\displaystyle-3^4\int_{u=1}^{u=-1}u^2\,\mathrm du$
$=\displaystyle3^4\int_{u=-1}^{u=1}u^2\,\mathrm du$
$=\displaystyle2\times3^4\int_{u=0}^{u=1}u^2\,\mathrm du$
$=54$

6 0

3 years ago

The difference of two numbers is 9 and the sum of the numbers is 55. what are the numbers?

yKpoI14uk [10]

The two numbers I think is 3&6 because this is a trick question

3 0

3 years ago

Ben sells homemade cards at a craft fair. He wants to earn more than $50 at the fair. He sells his cards for $2 and he has alrea

Kryger [21]

Answer:

He must sell 8 cards to reach the minimum goal.

Step-by-step explanation:

Giving the following information:

He wants to earn more than $50 at the fair.

He sells his cards for $2 and he has already earned $36.

First, we need to calculate the money required to reach the minimum goal:

51 - 36= $15

Now, we write the inequality:

2*x >15

x= number of cards sold.

x>15/2

x> 7.5

He must sell 8 cards to reach the minimum goal.

7 0

3 years ago

What is the effect on the graph of the function f(x) = x^2 when f(x) is changed to f(x − 6)

olya-2409 [2.1K]

Answer:

The comparison graph is also attached in 3rd figure. In the 3rd figure, the graph with vertex (0, 0) is representing $f(x) = x^2$ and $\:f\left(x\right)=\left(x-6\right)^2$ is represented as being shifted 6 units to the right as compare to the function $f(x) = x^2$ .

Step-by-step explanation:

When we Add or subtract a positive constant, let say c, to input x, it would be a horizontal shift.

For example:

Type of change Effect on y = f(x)

$y = f(x - c)$ horizontal shift: c units to right

So

Considering the function

$f(x) = x^2$

The graph is shown below. The first figure is representing $f(x) = x^2$ .

Now, considering the function

$\:f\left(x\right)=\left(x-6\right)^2$

According to the rule, as we have discussed above, as a positive constant 6 is added to the input, so there is a horizontal shift, 6 units to the right.

The graph of $\:f\left(x-6\right)=\left(x-6\right)^2$ is shown below in second figure. It is clear that the graph of $\:f\left(x-6\right)=\left(x-6\right)^2$ is shifted 6 units to the right as compare to the function $f(x) = x^2$ .

The comparison graph is also attached in 3rd figure. In the 3rd figure, the graph with vertex (0, 0) is representing $f(x) = x^2$ and $\:f\left(x\right)=\left(x-6\right)^2$ is represented as being shifted 6 units to the right as compare to the function $f(x) = x^2$ .

5 0

3 years ago

If x + 2 is a factor of x^3 - 2ax^2 +16, then value of a is i) 3 ii) 1 iii) 4

grandymaker [24]

Answer:

a=1 is the answer

Step-by-step explanation:

let

p(x)=x³-2ax²+16

put x= -2

p(-2)=(-2)³-2a(-2)²+16

p(-2)=-8+16-8a

p(-2)=8-8a

as (x+2) is a factor of p(x) then p(x) is equal to zero

8-8a=0

8=8a

a=1

i hope this will help you

3 0

3 years ago

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