Answer:
250
Step-by-step explanation:
As a decimal 253 and 19/23 can be written as 253.73
If we think about 253.73 being closer to 250 or 260, we can see that it is closer to 250, so that is the nearest ten we will round to.
Even if it is too difficult to convert to a decimal, if we round 19/23 to 23/23, our number becomes 254. The nearest ten is still 250.
Find the area of the surface.
The part of the sphere
x2 + y2 + z2 = 81
that lies above the plane
z = 4.
Parameterize this surface by
r (u, v) = 9 cos(u) sin(v) i + 9 sin(u) sin(v) j + 9 cos(v) k
with 0 ≤ u ≤ 2π and 0 ≤ v ≤ arccos(4/9)
See the attached sketch to see how we arrive at the upper limit for v.
Take the normal vector to the surface to be
n = ∂r/∂u × ∂r/∂v
n = -81 cos(u) sin²(v) i - 81 sin(u) sin²(v) j - 81 sin(v) cos(v) k
which has magnitude
||n|| = 81 sin(v)
Then the surface area is
[tex]\displaystyle \iint_S \|\mathbf n\| \,\mathrm du\,\mathrm dv = 81 \int_0^{2\pi} \int_0^{\arccos(4/9)} \sin(v)\,\mathrm dv\,\mathrm du \\\\ = 162\pi \int_0^{\arccos(4/9)} \sin(v)\,\mathrm dv \\\\ = -162\pi (\cos\left(\arccos\left(\frac49\right) - \cos(0)\right) \\\\ = 162\pi \left(1 - \dfrac49\right) \\\\ = \boxed{90\pi}[/tex]
If you're not familiar with surface integrals, you can instead use what's sometimes called the projection method. Let
z = f(x, y) = √(81 - x ² - y ²)
(where we take the positive square root because we're looking at a part of the top half of the sphere)
Projecting the surface down onto the (x, y)-plane, we see that it casts a "shadow" of a disk with radius √(9² - 4²) = √65. (Use the Pythagorean theorem to solve for the missing side of the triangle in the sketch.)
Then the surface S considered above is hovering over the set in the (x, y)-plane,
D = {(x, y) : x ² + y ² ≤ 65}
The area is then
[tex]\displaystyle \iint_D \sqrt{1 + \left(\dfrac{\partial f}{\partial x}\right)^2 + \left(\dfrac{\partial f}{\partial y}\right)^2} \,\mathrm dx\,\mathrm dy[/tex]
It's easier to compute this integral in polar coordinates, so we take
x = r cos(t )
y = r sin(t )
dx dy = r dr dt
and the region D is given by the set
{(r, t ) : 0 ≤ r ≤ √65 and 0 ≤ t ≤ 2π}
Then the integral would be
[tex]\displaystyle \iint_D \sqrt{1 + \left(\dfrac{\partial f}{\partial x}\right)^2 + \left(\dfrac{\partial f}{\partial y}\right)^2} \,\mathrm dx\,\mathrm dy = \iint_D \sqrt{1 + \frac{x^2+y^2}{81-x^2-y^2}}\,\mathrm dx\,\mathrm dy \\\\ = \iint_D \sqrt{\frac{81}{81-x^2-y^2}}\,\mathrm dx\,\mathrm dy \\\\ = \int_0^{2\pi} \int_0^{\sqrt{65}} r \sqrt{\frac{81}{81-r^2}}\,\mathrm dr\,\mathrm dt[/tex]
Substitute s = 81 - r ² and ds = -2r dr :
[tex]\displaystyle \int_0^{2\pi} \int_0^{\sqrt{65}} r \sqrt{\frac{81}{81-r^2}}\,\mathrm dr\,\mathrm dt = 2\pi \int_0^{\sqrt{65}} r \sqrt{\frac{81}{81-r^2}}\,\mathrm dr \\\\ = -9\pi \int_{81}^{16} \frac{\mathrm ds}{\sqrt s} \\\\ = 9\pi \int_{16}^{81} s^{-1/2}\,\mathrm ds \\\\ = 18\pi \left(\sqrt{81} - \sqrt{16}\right) \\\\ = \boxed{90\pi}[/tex]
A student bought 44 pencils for school. if he sharpened 8 of the pencils before school, what is his ratio of unsharpened pencils to sharpened pencils
Answer:
8:36
Step-by-step explanation:
if you sharpened 8 pencils out of 44 that means 8 pencils are sharpened and the other 36 aren't
HELP ME SOLVE THIS PLSS
no solution,
48x+43=47x+43
-43 -43
48x=47x
if x= 1
48 is not equal to 1
B
Answer:
B
Step-by-step explanation:
It's impossible to let these 2 equation have same answer!
help me guys I don't get it ?
Answer:
[tex]x =[/tex] [tex]-30[/tex]
Step-by-step explanation:
Solve for [tex]x[/tex] by simplifying both sides of the equation, then isolating the variable.
can anyone heelp me pls
Answer: lotion- semisolid
capsule- solid
suspension- liquid
Step-by-step explanation:
Serina and 2 friends go out for dinner. Their bill is $92.18. How much more would
they pay if they left a tip of 20% instead of a tip of 15%?
$9.22
$4.61
$6.91
$2.76
Answer:
$4.61
Step-by-step explanation:
To calculate a tip of 20%, you would perform the following:
$92.18 * 0.20 = $18.436
Similarly, for a tip of 15%:
$92.18 * 0.15 = $13.827
The difference would just be subtracting the two tip amounts from each other!
$18.436 - $13.827 = $4.609
Then you round to the nearest cent.
$4.609 ≈ $4.61
What is the distance from (-4, 0) to (2, 5)? Round your answer to the nearest hundredth.
Answer:
7.81
Step-by-step explanation:
Step-by-step explanation:
[tex]distance = \sqrt{(x2 - x1) ^{2} + (y2 - y1) ^{2} } [/tex]
Now, substitute the numbers into the equation,
[tex] \sqrt{(2 + 4) ^{2} +( 5 - 0)^{2} } [/tex]
distance = 7.81
brianlist me??
If F(x)=4x-1 and G(x)=2x-4 what is (FoG) (x)?
Can someone please help me on this problem I’m struggling
Answer:
No pictures so can't help ya.
Please help hurry ,,,.€.£\’smsmmsms
Can you help me on attached picture
What is the midpoint of the line segment from (5,-2) to (1,-5)?
Answer:
(3, -3.5)
Step-by-step explanation:
Using midpoint formula:
M = (x1 + x2/2 , y1 + y2/2)
By inserting the points you'll find the answer:
M = (5 + 1/2 , -2 + -5/2)
M = (6/2 , -7/2)
M = (3 , -3.5)
3x−(2x+1) simplify the expression
[tex]3x - (2x + 1) \\ = 3x - 2x - 1 \\ = x - 1[/tex]
Answer:x - 1
Answer: x-1
Step-by-step explanation: in the picture
need help with this algebra ii question
Vertex form: y = |x - h| + k
Vertex = (h, k)
G(x) was shifted 3 to the right and up 2.
G(x) = |x - 3| + 2
Hope this helps!! :)
Michelle has money in two savings accounts. One rate is 6%
and the other is 14%
. If she has $900
$
900
more in the 14%
account and the total interest is $209
, how much is invested in each savings account?
Answer:
$415 at 6% and $1315 at 14%
Step-by-step explanation:
She has x amount at 6%.
She has y amount at 14%.
y = x + 900
0.06x + 0.14y = 209
Since the first equation is already solved for y, we use the substitution method. Substitute x + 900 for y in the second equation and solve for x.
0.06x + 0.14(x + 900) = 209
0.06x + 0.14x + 126 = 209
0.2x = 83
x = 415
y = x + 900
y = 415 + 900
y = 1315
Answer: $415 at 6% and $1315 at 14%
please please help me
Solve equation for 3(2x - 5) - (2x - 5) = 6(4x + 5)
Answer:
the answer is negative two / x= -2
_________
[tex] \: [/tex]
[tex] \rm3(2x - 5) - (2x - 5 ) = 6(4x + 5)[/tex]
[tex] \rm6x - 15 - 2x - 5 = 24x + 30[/tex]
[tex] \rm4x - 20 = 24x + 30[/tex]
[tex] \rm4x - 24x = 30 + 20[/tex]
[tex] \rm - 20x = 50[/tex]
[tex] \rm \: x = \frac{50}{ - 20} [/tex]
[tex] \rm \: x = \boxed{ - 2 \frac{1}{2} }[/tex]
Solve for y 2 y = A 2Y + B + A B
Call me when you want, call me when you need
Call me in the morning, I'll be on the way
Call me when you want, call me when you need
Call me out by your name, I'll be on the way like
If f ( x ) is a linear function, f ( − 1 ) = 2 , and f ( 5 ) = − 5 , find an equation for f ( x ) . f ( x ) =__
show your work!
Step-by-step explanation:
Let's first find the slope
(-5-2)/(5--1) = -7/6
the equation should be
[tex]y = \frac{ - 7}{6} x + c[/tex]
To find c, we replace X with -1 and Y with 2
c= 5/6
So the equation is
[tex]y = \frac{ - 7}{6} x + \frac{5}{6} [/tex]
And if you multiply everything by 6 you get
6y = -7x +5
I keep getting D wrong
Answer:
The amount is $18548.38 and the interest is $2548.38
Steps for solution:
First you want to use the formula A=P(1+[tex]\frac{r}{n}[/tex])^n*t. A= total amount, P= principle or amount of money deposited, r= annual interest rate, n= number of times compounded per year. and t= time in years. In the problem we have P= $16000, r= 3%, n= 1 and t= 5 years. The first picture is the formula used to find the total amount. After we use the formula A=P+I, since A=18548.38 and P=16000. The second picture represents the interest after 5 years.
Re-write the quadratic function below in Standard Form
y = -(x - 1)^2 + 4
Answer:
2 2 y = a x 2 + b x + c ; a ≠ 0 2
Step-by-step explanation:
Enter an equation in standard form to model the linear situation. A bathtub that holds 41 gallons of water contains 11 gallons of water. You begin filling it, and after 5 minutes, the tub is full.
Answer: In this equation, let "x" equal the rate at which the tub will be filled. The tub holds 32 gallons, which will be one-half of the equation. The tub already contains 12 gallons, so this will be half of the other side of the equation. The rate is "x" gallons per minute, and the time it required was 5 minutes, so this would be "5x". Placing all these parts together gives an equation of (32 = 5x + 12) gallons per minute dispensed.
You are given the difference of the numbers of boys and girls in a class and the ratio of boys to girls. How many boys and how many girls are in the class?
3 more boys; 5 for every 4
9514 1404 393
Answer:
15 boys12 girlsStep-by-step explanation:
The difference in ratio units is 5 - 4 = 1. The difference in actual quantity is 3, so 1 ratio unit must represent 3 students.
There are 5×3 = 15 boys.
There are 4×3 = 12 girls.
Jenelle bought a home for $260,000, paying 10% as a down payment, and financing the rest at 5.4% interest for 30 years. Round your answers to the nearest cent. How much money did Jenelle pay as a down payment? $ What was the original amount financed? $ What is her monthly payment? $ If Jenelle makes these payments every month for thirty years, determine the total amount of money she will spend on this home. Include the down payment in your answer. $
Step-by-step explanation:
260000*0*54*30
$421200
Two standard dice are thrown. Determine the theoretical probability that the sum is
a) 4 b) 7
c) an even number d) not a 6 e) not a perfect square
Step-by-step explanation:
there are 36 (6×6) possible results and number combinations for 2 dice.
a)
to create a sum of 4 we need one of the following combinations :
1 3
2 2
3 1
so, 3 out of the overall possible 36 possibilities.
and that means the probability is 3/36 = 1/12
b)
to create a sum of 7 we need one of the following combinations :
1 6
2 5
3 4
4 3
5 2
6 1
so, 6 out of the overall possible 36 possibilities.
and that means a probability of 6/36 = 1/6
c)
since the possible outcomes in that regard are only 2 (even and uneven), with equal balance the probability is 1/2.
make it more formal ?
to get an even sum, every possible number on one die can be combined with 3 possibilities on the other.
1 can be combined with 1, 3, 5
2 with 2, 4, 6
3 with 1, 3, 5
4 with 2, 4, 6
5 with 1, 3, 5
6 with 2, 4, 6
these are 6×3 = 18 combinations of of the possible 36.
so, the probability is 18/36 = 1/2
d)
not a 6 ?
so, what does that mean ?
we are looking only at 5 possible outcomes per die.
that is 5×5 = 25 combinations out of the possible 36.
that means that probabilty is 25/36.
e)
not a perfect square ?
we have in the range of the possible sums with 2 dice (2 .. 12) only two perfect squares : 4 and 9
so, the sum must NOT be 4 AND NOT be 9.
so, here it might be easier to count the unwanted cases and then deduct the probability from 1 to express the opposite.
the combinations to get 4 we have already under a)
3 combinations with 3/36=1/12 probability.
the combinations to get 9
1 none
2 none
3 6
4 5
5 4
6 3
so, 4 combinations with a probability of 4/36 = 1/9
therefore, we have (3+4) = 7 cases out of the possible 36 we actually want to avoid.
so, the probability to get any one of the other (desired) combinations is therefore (36-7)/36 = 29/36
The probabilities are:
a) 0.083b) 0.167c) 0.5d) 0.861e) 0.806.How to get the probabilities?The probability for a given outcome is given by the quotient between the number of combinations that give that outcome and the total number of combinations.
Here each dice has 6 possible outcomes, so the total number of combinations for the two dice is:
6*6 = 36 combinations.
a) Here we need to count how many combinations add to 4, the notation I will use is:
dice 1 dice 2
1 3
3 1
2 2
There are 3 combinations that add to 4, then the probability of getting a sum equal to 4 is:
P = 3/36 = 0.083
b) Same thing as before, this time we count the combinations that add to 7.
dice 1 dice 2
1 6
6 1
5 2
2 5
4 3
3 4
There are 6 combinations that add to 7, so the probability is:
P = 6/36 = 0.167
c) The possible even numbers are: {2, 4, 6, 8, 10, 12}
A way of doing this, is:
If the first dice is even/odd, then the second also must be even/odd.
Then the probability is just 1/2 = 0.5 (because there are the same number of odd and even numbers in a dice).
d) The sum must not be equal to 6, the combinations that add up to 6 are:
dice 1 dice 2
2 4
4 2
3 3
1 5
5 1
So 5 combinations add up to 6, then there are 31 combinations that do not add up to 6, this means that the probability of not getting a sum equal to 6 is:
P = 31/36 = 0.861
e) The perfect squares are 4 and 9, we already know that 3 combinations add up to 4, now let's find the combinations that add up to 9.
dice 1 dice 2
6 3
3 6
5 4
4 5
So 4 combinations add up to 9, then there is a total of 7 combinations that give a perfect square, then there are 29 combinations that do not add to a perfect square.
The probability is:
P = 29/36 = 0.806
If you want to learn more about probability, you can read:
https://brainly.com/question/251701
HELPPPPPPPP!!!! In 1.6, we learned about rational exponents. In a rational exponent, the numerator is the power that the base of the exponent is being raised to and the denominator is the root that is being taken of that base. If the numerator is odd, why is there only one root?
Question Find the slope of the line. (-1,3) (3,3)
List the number which round off to 300
Answer fast please!!!!
Answer:
6z + 9
Step-by-step explanation:
distribute 3/4 by 8z to get 6z
distribute 3/4 by 12 to get 9
According to the new remuneration scheme, the starting pay of a lecturer a is RM3,087 per month and the annual increment is RM195. Ahmad, who is 25 years old, becomes a lecturer in a university. (a) What will his monthly salary be when he is 45 years old? (b) What will his age be when he gets a monthly payment of RM8,937?
Step-by-step explanation:
arithmetic sequence : every new item of the sequence is created by adding a constant term to the previous item - in this case 195.
a1 = 3087 (that's our starting value)
a2 = a1 + 195
a3 = a2 + 195 = a1 + 2×195
an = a1 + (n-1)×195
a)
when he is 45 years old, that is 20 years (and 20 annual increments) plus to our starting value.
so, n = 1+20 = 21
a21 = a1 + 20×195 = 3087 + 20×195 = 6987
so, when he is 45 years old, his monthly salary will be RM6,987
b)
how many years (= how big is n) until he gets 8937 ?
8937 = a1 + (n-1)×195 = 3087 + (n-1)×195 =
= 3087 + n×195 - 195 = 2892 + n×195
6045 = n×195
n = 6045/195 = 31
so, a31 = 8937
and that means, he has to work 30 additional years (31 minus the starting level 1) to earn monthly RM8,937.
that means he will be 25+30 = 55 years old.