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Equations/345381: Hi there, I was wondering if someone could show me how to find the derivative of e^sin(x^2)with some steps on to do it please.
Thankyou
sicnarf
1 solutions

Answer 246971 by Alan3354(30982) About Me  on 2010-09-19 21:32:20 (Show Source):
You can put this solution on YOUR website!
derivative of e^sin(x^2)
f' = e%5Esin%28x%5E2%29%2Acos%28x%5E2%29%2A2x


Rate-of-work-word-problems/344860: It takes 2 printers 108 mins to complete 5580 pages---working alone 1st printer takes 90 mins---how long will it take each printer to do the job alone--and the speed of each printer?
Thanks
1 solutions

Answer 246736 by Alan3354(30982) About Me  on 2010-09-18 19:09:45 (Show Source):
You can put this solution on YOUR website!
It takes 2 printers 108 mins to complete 5580 pages---working alone 1st printer takes 90 mins---how long will it take each printer to do the job alone--and the speed of each printer?
-------------------
One printer takes less time than the 2 of them together.


Polygons/344835: Which of the following cannot be the measure of 1 exterior angle of a regular polygon?
A) 2 B) 20 C) 25 D) 51 and 3/7 E) 120
1 solutions

Answer 246730 by Alan3354(30982) About Me  on 2010-09-18 18:49:11 (Show Source):
You can put this solution on YOUR website!
The total of exterior angles of ALL polygons is 360º
The measure of the exterior angles of a regular polygon has to be 360/an integer, so 360 divided by the angle has to be an integer.
--------
Check each one and see if 360/it is an integer.
PS D does give an integer, I'll save you having to diddle with fractions.
It's A, B, C or E


Geometry_Word_Problems/344818: suppose the measures of the interior angles of convex nonagon are nine consecutive whole numbers. Find the measure of the second to smallest angle.
1 solutions

Answer 246706 by Alan3354(30982) About Me  on 2010-09-18 17:48:39 (Show Source):
You can put this solution on YOUR website!
The total of the interior angles on a 9-gon is 1260º
9 consecutive integers add to 1260.
1260/9 = 140, the middle number.
--> 136, 137, 138, 139, 140, 141, 142, 143 and 144


test/344815: Please help me solve this equation: +int%28+%281-x%29%5E2010%2C+dx%2C+0%2C+1+%29+
1 solutions

Answer 246700 by Alan3354(30982) About Me  on 2010-09-18 17:03:17 (Show Source):
You can put this solution on YOUR website!
= -%281-x%29%5E2011%2F2011+%2B+C
--> 0 + 1/2011
= 1/2011


Probability-and-statistics/344773: Assume your alarm clock has a 0.195% probability of working on every given morning. What is the probability that your alarm clock will not work on the morning of a important final exam?
1 solutions

Answer 246698 by Alan3354(30982) About Me  on 2010-09-18 16:53:07 (Show Source):
You can put this solution on YOUR website!
0.195% of working, the same as every day.
The probability of not working is 100% minus that
= 99.805% of not working
I hope you didn't pay a lot for it.


Linear-equations/344788: i need help solve by elimation method: 5x+6y=4 and 10x+12y=8
thank you
1 solutions

Answer 246697 by Alan3354(30982) About Me  on 2010-09-18 16:50:44 (Show Source):
You can put this solution on YOUR website!
What sort of help?


Quadratic_Equations/344805: how do you factor 2x^2+5x-3
1 solutions

Answer 246696 by Alan3354(30982) About Me  on 2010-09-18 16:50:13 (Show Source):
You can put this solution on YOUR website!
how do you factor 2x^2+5x-3
It will be (x + a)*(2x + b)
a*b = -3 so the signs will be different
2a + b = 5
--> (2x - 1)*(x + 3)


Quadratic_Equations/344803: Please Help me solve: 4x^4=4000x
1 solutions

Answer 246695 by Alan3354(30982) About Me  on 2010-09-18 16:35:56 (Show Source):
You can put this solution on YOUR website!
Divide both sides by 4x


Equations/344662: if it takes a colony of termites to devour a block of wood that is 2 inches wide, 2 inches long, 2 inches high, then how long will it take them to devour a block of wood that is 4 inches wide, 4inches long and 4 inches high. assume they keep eating at the same rate. show the solution.
1 solutions

Answer 246667 by Alan3354(30982) About Me  on 2010-09-18 11:26:25 (Show Source):
You can put this solution on YOUR website!
8 times as long


test/344704: the sum of four consecutive integers is 238. find the integers

1 solutions

Answer 246666 by Alan3354(30982) About Me  on 2010-09-18 11:17:40 (Show Source):
You can put this solution on YOUR website!
the sum of four consecutive integers is 238. find the integers
--------
238/4 = 59.5, the center
--> 58,59,60,61


test/344621: This is a calc. question; please help!
A telephone wire is to be laid from the telephone company to an island 7 mi off shore at a cost of $200,000 per mile along the shore line and $300,000 per mile under the sea. How should the wire be laid @ the least expensive cost if the distance along the shoreline in 12 miles. What is the cost?
1 solutions

Answer 246655 by Alan3354(30982) About Me  on 2010-09-18 10:37:22 (Show Source):
You can put this solution on YOUR website!
A telephone wire is to be laid from the telephone company to an island 7 mi off shore at a cost of $200,000 per mile along the shore line and $300,000 per mile under the sea. How should the wire be laid @ the least expensive cost if the distance along the shoreline in 12 miles. What is the cost?
------------
This forms a right triangle with the shore side 12 miles long and the base = 7 miles to the island.
x = the distance along the shore from the perpendicular from the island.
The distance on land = 12 - x miles
The distance under water = sqrt(x^2 + 49) miles
The cost C = 200*(12-x) + 300*sqrt(x^2 + 49) (Cost in $1000)
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dC/dx = -200 + 300x*(x^2 + 49)^(-1/2) = 0
3x*(x^2 + 49)^(-1/2) = 2
3x = 2sqrt(x^2 + 49)
9x^2 = 4x^2 + 196
x^2 = 196/5
x = 2.8sqrt(5) miles for minimum cost
---------------------------------------
Length of cable = 12 - 2.8sqrt(5) + sqrt(88.2)
L = 12 - 2.8sqrt(5) + 4.2sqrt(5)
L = 12 + 1.4sqrt(5) miles total
L =~ 15.13 miles
-----------------
Cost = 200*(12-x) + 300*sqrt(x^2 + 49) (Cost in $1000)
C = 2400 - 560sqrt(5) + 1260sqrt(5) = 2400 + 600sqrt(5)
Cost =~ $3,741,641





Complex_Numbers/344630: Find the zero of the function: f(x)=12? Thanks
1 solutions

Answer 246580 by Alan3354(30982) About Me  on 2010-09-17 22:45:00 (Show Source):
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There is no zero, it's always 12.


expressions/344625: Can you help me with this problem? The answer is suppose to be -30, but I keep getting a positive 30. -a[(-x-a)-(x-y)]. The key is a=-3, x=4, y=-5
1 solutions

Answer 246571 by Alan3354(30982) About Me  on 2010-09-17 21:03:30 (Show Source):
You can put this solution on YOUR website!
-a[(-x-a)-(x-y)].
The key is a=-3, x=4, y=-5
---------------
= 3[(-4+3) - (4+5)]
= 3[-1 - 9]
= -30


Geometric_formulas/344613: Can someone please help me solve this equation? I've tried everything, and I still can't figure it out.
Question:
If m Any one can help me that would be wonderful! Thanks in advance!

1 solutions

Answer 246570 by Alan3354(30982) About Me  on 2010-09-17 21:01:21 (Show Source):
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= 125 - 78
= 47º


expressions/344585: the numbers in a 4 by 4 matrix were a. -5304, b.2312,c.6730,d.1530
1 solutions

Answer 246560 by Alan3354(30982) About Me  on 2010-09-17 18:24:27 (Show Source):
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a 4 by 4 matrix has 16 numbers.
You listed 4.
And, what is it you want to do?


Evaluation_Word_Problems/344504: What is the acceleration of a car that moves from a speed of 5.0 m/s to a speed of 15 m/s during a time of 6.0 s?
1 solutions

Answer 246506 by Alan3354(30982) About Me  on 2010-09-17 15:00:18 (Show Source):
You can put this solution on YOUR website!
What is the acceleration of a car that moves from a speed of 5.0 m/s to a speed of 15 m/s during a time of 6.0 s?
----------
a = diffv/t = (15 - 5)/6
a = 5/3 m/sec/sec


Equations/344375: A distant planet has 4 moons. The first moon takes 6 earth years to circle the planet. The 4th moon takes 18 earth years to circle the planet. How many earth years will it take for the 4 moons to be in conjunction?
1 solutions

Answer 246500 by Alan3354(30982) About Me  on 2010-09-17 14:48:20 (Show Source):
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The periods of the other 2 moons has to be given.


Radicals/344497: Applications
We can determine the time it would take an object to fall (if there were no air resistance) by using the formula t=1/4√d where d is the distance
A. how long does it take a quarter dropped from a 35foot roof to reach the ground?
B. If there are 5280 feet in one mile, how long would it take an object to fall 1-1/2 miles?
C. If it takes an object 5.9 seconds to fall d feet, how tall is the object?

I tried sloving with a graphic calculator but I am not certain on how to show work. Please help

1 solutions

Answer 246498 by Alan3354(30982) About Me  on 2010-09-17 14:41:52 (Show Source):
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t=sqrt(d)/4 where d is the distance
A. how long does it take a quarter dropped from a 35foot roof to reach the ground?
t = sqrt(35)/4 seconds
----------------
B. If there are 5280 feet in one mile, how long would it take an object to fall 1-1/2 miles?
1.5 miles = 7920 feet
t = sqrt(7920)/4
----------------
C. If it takes an object 5.9 seconds to fall d feet, how tall is the object?
If you mean it falls from the height of the object:
d = 16t^2 = 16*5.9^2


Linear-equations/344500: Trying to solve the following (linear equation):
y=-x
1 solutions

Answer 246450 by Alan3354(30982) About Me  on 2010-09-17 13:02:56 (Show Source):
You can put this solution on YOUR website!
It is solved for y.
You can solve for x:
x = -y


Surface-area/344429: can you show me how to work these out please:
1) The formula S=4 π r2 gives the surface area of a sphere of radius r. Jupiter’s radius is 71 492 000 metres. Use the formula t0 estimate the surface area of Jupiter.
2) Atomic particles: Atoms are made up of protons, neutrons and electrons. The mass of a proton is 0.000 000 000 000 000 000 000 000 001 673kg.
This is 1836 times as heavy as an electron.
What is the mass of an electron?
How many protons are needed to make a mass of 1kg?

3) The wave length of red light is 7x10-7 m and that of violet light is 4x10-7
Metres. What is the difference between these wavelengths
1 solutions

Answer 246443 by Alan3354(30982) About Me  on 2010-09-17 11:39:09 (Show Source):
You can put this solution on YOUR website!
can you show me how to work these out please:
1) The formula S=4 π r2 gives the surface area of a sphere of radius r. Jupiter’s radius is 71 492 000 metres. Use the formula t0 estimate the surface area of Jupiter.
Sub the number for r
Area+=+4%2Api%2A%2871492000%29%5E2
Do it with a calculator.
----------------------------
2) Atomic particles: Atoms are made up of protons, neutrons and electrons. The mass of a proton is 0.000 000 000 000 000 000 000 000 001 673kg.
This is 1836 times as heavy as an electron.
What is the mass of an electron?
Mass of the proton is 1.673E-27 kg
Mass of the proton = 1.673E-27/1836 = 16730E-31/1836
=~ 9.112E-31 kg
-----------------
How many protons are needed to make a mass of 1kg?
# = 1/mass =~ 5.977E26 protons/kg
--------------------------------------
3) The wave length of red light is 7x10-7 m and that of violet light is 4x10-7
Metres. What is the difference between these wavelengths
7E-7 - 4E-7 = 3E-7 (or 3*10^-7) meters


Travel_Word_Problems/344373: a football field is 100 yards. it takes 60 people from head to toe to fill the field. what is the average height for each person?
1 solutions

Answer 246441 by Alan3354(30982) About Me  on 2010-09-17 11:09:48 (Show Source):
You can put this solution on YOUR website!
100/60 = 5/3 yards


Linear-systems/344404: Find the equation of the line through pair of points (4,0) and (-8,5). Write equation on Ax +By = C form
1 solutions

Answer 246431 by Alan3354(30982) About Me  on 2010-09-17 10:31:13 (Show Source):
You can put this solution on YOUR website!
Given 2 points example.
Find the equation of the line thru the points (2,1) and (3,5)
---------------------
This is a 2 step process. First find the slope of the line thru the points.
slope, m = diffy/diffx
m = (5-1)/(3-2)
m = 4
---------
Now use y = mx + b with either point to find b, the y-intercept.
y = mx + b
5 = 4*3 + b
b = -7
-------
y = mx + b
y = 4x - 7 is the answer.
------------------------
Another approach using determinants:
|x y 1|
|2 1 1| = 0
|3 5 1|
--------
x(1-5) - y(2-3) + 1(10-3) = 0
-4x + y + 7 = 0
y = 4x - 7
---------
For further assistance, or to check your work, email me via the thank you note
or at Moral Loophole@aol.com


Circles/344426: How many prime numbers less than 200 are 1 more than the square of an integer?
1 solutions

Answer 246387 by Alan3354(30982) About Me  on 2010-09-17 08:51:30 (Show Source):
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Check the even numbers from 2 to 14
Square them and add 1
2 --> 5
4 --> 17
etc


Polynomials-and-rational-expressions/344438: A triangle has a side of length x . The second side of the triangle is 2 inches
longer than the first side. The third side is 4 inches longer than the first side. The
square of the first side plus the square of the second side is equal to the square of the
third side. What is the length if each side of the triangle? USE THE 5-STEP METHOD.
This is how much I've figured out so far:
x²+(x+2)²=(x+4)²
x²+x²+2x+2x+4 = x²+4x+4x+16
x(4)+4+4 = x²+8x+16
-4x -4x
x(4)+4 = x² +4x+16
x(4)+4-4 = x²+4x+16-4
x(4) = x²+4x+12
-x² = -x²
So if x²=4x+12, SOLVE FOR X.
I think the answer is 6, but I don't know the procedure.
I.E,
x=5 x=6
25=20+12 36=24+12
25=32 36=36
6²+8²+10²
36+64 =100
x=6
I need help ASAP, please!!! Thank you!! :)

1 solutions

Answer 246381 by Alan3354(30982) About Me  on 2010-09-17 08:40:39 (Show Source):
You can put this solution on YOUR website!
x²+(x+2)²=(x+4)²
x²+x²+2x+2x+4 = x²+4x+4x+16 It's ok this far
---------
x(4)+4+4 = x²+8x+16 ????
-------------
2x%5E2+%2B+4x+%2B+4+=+x%5E2+%2B+8x+%2B+16
x%5E2+-+4x+-+12+=+0
(x-6)(x+2) = 0
x = -2 (Ignore)
x = 6


Radicals/344443: sqrt of x sqr -17=8
1 solutions

Answer 246375 by Alan3354(30982) About Me  on 2010-09-17 08:34:15 (Show Source):
You can put this solution on YOUR website!
If you mean
sqrt%28x%5E2+-+17%29+=+8
Square both sides
x%5E2+-+17+=+64
x%5E2+=+81
x = ± 9


Travel_Word_Problems/344298: With a head wind, a plane traveled 1000 miles in 4 hours. With the same wind as a tail wind, the return trip took 3 hours and 20 minutes, Find the plane's air speed and the wind speed.
1 solutions

Answer 246303 by Alan3354(30982) About Me  on 2010-09-16 21:31:19 (Show Source):
You can put this solution on YOUR website!
1000/4 = 250 mph
1000/(10/3) = 300 mph
The plane's airspeed is the average (250 + 300)/2 = 275 mph
The windspeed is the difference, 275 - 250 = 25 mph
-----------------------
headwind is one word.
so is tailwind.


Exponents/344255: Solve the given equation for X:
4x^8
----- = 16,384
x^12

Write your answers in ascending order.
x = ___ , ___

Please help, I've not done a problem like this for years, I've forgotten the methods to get the correct answers.

1 solutions

Answer 246290 by Alan3354(30982) About Me  on 2010-09-16 20:33:08 (Show Source):
You can put this solution on YOUR website!
4x%5E18%2Fx%5E12+=+16384
x%5E18%2Fx%5E12+=+x%5E%2818-12%29+=+x%5E6
--> 4x%5E6+=+16384
x%5E6+=+4096+=+2%5E12
Either way, x+=+4096%5E%281%2F6%29
or x+=+2%5E2
x = 4 is the principal answer
-----------------
x%5E6+=+4096 has 6 answers
x = 4 or x = -4 are the most obvious



Money_Word_Problems/344233: Kurt invest $5,000 in an account with a 6.25% intreast rate a year. After how many years will his investment be $10,000?
I really prefer a example and formula so I know how to do it myself instead of just a answer. Thanks.
1 solutions

Answer 246285 by Alan3354(30982) About Me  on 2010-09-16 20:19:21 (Show Source):
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Kurt invest $5,000 in an account with a 6.25% intreast rate a year. After how many years will his investment be $10,000?
FV = PV*(1 + r)^n ... r = %interest/100, n = years, FV = Future Value, PV = present value
-------------
10000 = 5000*(1 + 0.0625)^n
(1.0625)^n = 2
n*log(1.0625) = log(2)
n = log(2)/log(1.0625)
n =~ 11.4 years
-----------------
It's as good an example as any.


Inverses/344244: How do you work the problem 2y=4x=8?
1 solutions

Answer 246282 by Alan3354(30982) About Me  on 2010-09-16 20:15:12 (Show Source):
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Not possible, too many equal signs.
Plus, you have to define "work the problem."


Word_Problems_With_Coins/344172: same number of nickels and dimes. $3.00, how many coins?
1 solutions

Answer 246281 by Alan3354(30982) About Me  on 2010-09-16 20:14:13 (Show Source):
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Hint: Each pair = 15 cents