Wednesday
August 20, 2014

Posts by ann


Total # Posts: 1,207

Calculus
A holding pen for fish is to be made in the form of a rectangular solid with a square base and open top. The base will be slate that costs $4 per square foot and the sides will be glass that costs $5 per square foot. If the volume of the tank must be 50 cubic feet, what ...
February 17, 2014

math
If an apartment complex will need painting in 3 1 2 years and the job will cost $25,000, what amount needs to be deposited into an account now in order to have the necessary funds? The account pays 12% interest compounded semiannually.
February 16, 2014

physics
How far from Earth will Venus be today?
February 16, 2014

Astronomy
What five object were found in the sky on February 5, 2014 at 9 pm.
February 15, 2014

Astronomy
a.According to the Starry Night program, which constellation the Sun was actually in at the instant of a person birth on August 12, 1953. b. What was the right ascension of the Sun on the moment a person was born on August 12, 1953. c. What constellation is this position in?
February 13, 2014

maths
a grocey man sells 300 apples at Rs 50 per dozen. he sells 200 apples from it at Rs 50 for 10 apples. what will the price per apple for the remaining apples to get an overall profit of 12%
February 12, 2014

math
donna brings 32 slices of apples and oranges to the party. there are 3 times as many oranges than apples. how many apples are there
February 6, 2014

biostatistics
Seventeen people has been exposed to a particular disease. Each one independently has a 40% chance of contracting the disease. A hospital has the capacity to handle 10 cases of the disease. What is the probability that the hospital's capacity will be exceeded? a- .011 b- ....
February 5, 2014

statistics
Height of children in kindergarten described by normal mode with mean 39.2 inches and standard deviation of 1.9 inches. What percent of children can expect to be less than 38 inches tall?
February 1, 2014

Pre-Calculus
Actually I figured out that you use both, and ended up with 16x^7(x^2-9)^7 + 6x^5(x^2-9)^8. but I don't understand how that simplifies to 2x^5(x^2-9)^7(11x^2-27)?
January 29, 2014

Pre-Calculus
Find dy/dx if y= x^6[(x^2-9)^8]? So the answer is supposed to be 2x^5[(x^2-9)^7](11x^2-27), but I don't understand how to get it. Do you use product rule, chain rule or both? thanks
January 29, 2014

Math
An athletes long jump rounded to the nearest metre was 8 m. Whar are the longest and shortest lengths the jump could have been in decimals to the hundredths ?
January 29, 2014

Math
An athletes long jump rounded to the nearest metre was 8 m. What are the longest and shortest lengths the jump could have been in decimals to the hundredths.
January 29, 2014

geometry
Calculate lengths of ap,bp,cp. A(0,0) B(0,2k) C(2h,0) P(h,k)?
January 22, 2014

algerbra
sasha researched the size of zoos in her state. she found that the zoo in the north part of the state is almost twice as large as the zoo in the south. she also found that the zoo in the south part of the state has 200 fewer than twice the number of animals as the northern zoo...
January 9, 2014

math
find the slope of the linethat passes through the given points (4,6) and (4,4)
December 19, 2013

reimbursement methodologies
which of the following was the governments way of controlling skyrocketing health care costs?
December 18, 2013

Pre-Calculus
y= ((2-3x^(1/x))/(2+3x^(1/x)) Is the horizontal asymptote y= 1 or y= -1?
December 18, 2013

Pre-Calculus
Is it possible to factor x^3 - 9x^2 + 24x - 20 and solve for x by hand? I tried using the grouping method and got x^2(x-9) + 4(6x-5) but how can I continue solving for x? If I use a calculator I get x= 2 and 5 but is it possible to find this by hand? thanks
December 16, 2013

math
Evaluate definite integral of (2x+2)(x^2 + 2x -5)^5dx upper limit 2 and lower limit 1
December 15, 2013

music
I need help I'm about to take my Comprehensive Final Exam on Foundations of Music A STEP BY STEP APPROACH TO MUSIC THEORY. I'm so confused I don't want to fail my test I failed the last two I'm afraid of failing. Please help me.
December 10, 2013

Math
Oh I think I know what I did wrong now
December 7, 2013

Math
Cassandra is two thirds as old as Jeremy. Three years ago she was half as old as Jeremy. How old are Cassandra and Jeremy? I got this question wrong and was wondering what I did wrong. This is what I did. Now 3 years ago Cassandra| C | C-3 Jeremy | J | J-3 C=2/3J C-3=1/2(J-3...
December 7, 2013

Pre-Calculus
Solve the equation 2x + 5y - 3z = -1. Write the general solution as a matrix equation. I did some guessing and ended up getting this much: [x]= [-1/2 _ _ ] X [1] [y]= [ 0 1 0 ] X [s] [z]= [ 0 0 1 ] X [t] however I still can't figure out the last two values in the first row
December 6, 2013

Pre-Calculus
I still don't really understand how to do it... I did some guessing and ended up getting this much: [x] [-1/2 _ _] [1] [y]= [0 1 0] X [s] [z] [0 0 1] [t] however I still can't figure out the last two values in the first row.
December 6, 2013

Pre-Calculus
[x] [...] [1] [y]= [...] X [s] [z] [...] [t] to align it better I put dots in the blanks...and I think s and t are free variables that be be any real number
December 6, 2013

Pre-Calculus
Solve the equation 2x + 5y - 3z = -1. Write the general solution as a matrix equation. [x] [ ] [1] [y]= [ ] X [s] [z] [ ] [t] I'm supposed to fill in that blank in the middle, but I don't understand how to solve this if I'm only given one equation. please explain
December 6, 2013

Pre-Calculus
if not, then can you show me how to do this with the substitution method or something?
December 4, 2013

Pre-Calculus
Consider the chemical reaction aC2H6 + bCO2 + cH2O → dC2H5OH, where a, b, c, and d are unknown positive integers.? The reaction must be balanced; that is, the number of atoms of each element must be the same before and after the reaction. For example, because the number ...
December 4, 2013

Pre-Calculus
wow that was a silly mistake I didn't see the x next to 500 and thought I could just subtract it from 1000 thank you!
November 20, 2013

Pre-Calculus
A piece of equipment has cost function C(x)=50x^2 + 1000 and its revenue function is R(x)= 500x - x^2, where x is in thousands of items. What is the least number of items that must be sold in order to break even? 50x^2 + 1000 = 500x - x^2 50x^2 + x^2 + 500= 0 51x^2 + 500 = 0 ...
November 20, 2013

Pre-Calculus
Wow, I didn't realize that finding (x-2) was already finding the equation of the line. Thanks!
November 19, 2013

Pre-Calculus
The graph of f(x)= (x^2 - 11x + 18)/(x-9) consists of a line and a hole. Find the equation of the line and the coordinates of the hole. I really have no idea how to do this. I tried factoring it and ended up with (x-2), but I don't know how that helps me. please help
November 19, 2013

Pre-Calculus
oh yeah thanks I forgot that the reciprocal had to be negative
November 19, 2013

Pre-Calculus
What is the equation of the line passing through (4, 2) and perpendicular to the line passing through the points (9,7) and (11,4)? Here's what I did: (7-4)/(9-11) = -3/2 y-2= (-2/3)(x-4) y-2=(-2x/3) + (8/3) y = (-2x/3) + 14/3 but the answer key says that it's y=(2x/3...
November 19, 2013

Pre-Calculus
thanks...though I asked for (-3,-1).
November 17, 2013

Pre-Calculus
Find the slope of the tangent line to the curve 2(x^2+y^2)^2=25(x^2−y^2) at the point (−3,−1)? Here's what I did: 2(x^4 + y^4) = 25(x^2-y^2) 2x^4 + 2y^4 = 25x^2 - 25y^2 8x^3 + 8y^3(dy/dx) = 50x - 50y(dy/dx) d/dx(8y^3 + 50y) = 50x - 8x^3 d/dx = (50x-8x^3...
November 17, 2013

Pre-Calculus
thanks
November 14, 2013

Pre-Calculus
no it's actually 1x and 1xy. It's not division.
November 14, 2013

Pre-Calculus
Find the slope of the tangent line to the curve √(1x+2y) + √(1xy) = 8.24 at the point (2,8)? I know you have to use implicit differentiation, but the radicals keep making me mess up algebraically. Is the changing the radicals to exponents the fastest way? please ...
November 14, 2013

Pre-Calculus
nevermind I made a mistake it's p(x)=-1x/10 + 465
November 13, 2013

Pre-Calculus
A manufacture has been selling 1050 television sets a week at 360 dollars each. A market survey indicates that for each 20 -dollar rebate offered to a buyer, the number of sets sold will increase by 200 per week. p(x)=1x/10 + 465 How large of a rebate should the company offer ...
November 13, 2013

Pre-Calculus
Thank you all so much!
November 12, 2013

Pre-Calculus
When you do implicit differentiation, how does D = √(x^2 + 8x + 12) turn into dD/dt = [(x + 4)(dx/dt)]/√(x^2 + 8x + 12)? please explain...I don't even understand where the (x+4) comes from. D means distance, but that's irrelevant
November 12, 2013

Physics
laf is standing on a sheet of ice that covers the football stadium parking lot in Buffalo, New York; there is negligible friction between his feet and the ice. A friend throws Olaf a ball of mass 0.400kg that is traveling horizontally at 11.5m/s . Olaf's mass is 65.2kg. If...
November 12, 2013

physics
In the construction of bridges and skyscrapers, gaps must be left between adjoining steel beams to allow for the expansion and contraction of the metal due to heating and cooling. The temperature of a sample of iron with a mass of 10.0g changed from 50.4oC to 25.0oC with the ...
November 3, 2013

Science
a wagon that has a mass of 8kg? If the net force on a wagon is 4N, what is the wagon’s acceleration?
November 3, 2013

Pre-Calculus
thanks
November 3, 2013

Pre-Calculus
How is -16/(4x+6)^5 and -1/(2(2x+3)^5) equivalent? I think -1/2(2x+3)^5 is the more simplified version of the two, but I just can't figure out how -16/(4x+6)^5 simplifies to -1/(2(2x+3)^5). please explain
November 3, 2013

Pre-Calculus
thank you
October 31, 2013

Pre-Calculus
Let f(x) = [(√x)-7]/[(√x)+7]. What is f'(x)? What is the easiest way to find the derivative of this? Should I remove all the radicals and use quotient rule, like f'(x)= ((x^0.5) + 7)(0.5x^-0.5) - ((x^0.5)-7)(0.5x^-0.5) / ((x^0.5) + 7)^2 Is this right? How ...
October 31, 2013

math
find an equation of the line passing through the pair of points. write the equation in Ax+By=C (-9,7), (-10,-4)
October 29, 2013

math
find an equation of the line with the given slope that passes through the given point. write the equation in the form Ax+By=C M=3/2, (7,-3)
October 29, 2013

Ancient History Art
Can the extravagance and costs, both of money and lives, be justified in the opulent architecture commissioned by "divinely empowered" individuals of ancient cultures? Name a comparable example from today's society.
October 27, 2013

math
ok 35020/1.03=34000 ....but where did the 1.03 come from?
October 23, 2013

math
Find last years salary if after a 3% pay raise this years salary is $35,020
October 23, 2013

Pre-Calculus
this is weird...but thanks!
October 19, 2013

Pre-Calculus
Determine the derivative at the point (2,−43) on the curve given by f(x)=7−7x−9x^2. I know that the answer is -43, but I was wondering if it was just a coincidence that the derivative at the point (2,−43) is -43, or is there a reason why -43 is the same...
October 19, 2013

Pre-Calculus
Thank you very much
October 18, 2013

Pre-Calculus
Yeah, that was a stupid mistake... But now I have another question. Isn't the final answer supposed to be in −1/(ah+b) form? Why is my answer 1/(196+14h) still positive? Did I do something else wrong?
October 18, 2013

Pre-Calculus
Let f(x) be the function 1/(x+9). Then the quotient [f(5+h)−f(5)]/h can be simplified to −1/(ah+b). What does a and b equal to? So I understand the overall concept, and did f(5+h) = 1/(14+h) and f(5) = 1/14. Then to subtract the two, you get the common denominator ...
October 18, 2013

Pre-Calculus
The Hotel Ventor has 400 rooms. Currently the hotel is filled. The daily rental is $ 600 per room. For every $6 increase in rent the demand for rooms decreases by 7 rooms. Let x = the number of $ 6 increases that can be made. What should x be so as to maximize the revenue of ...
October 14, 2013

Pre-Calculus
Nevermind, now I see that all the question asks for is the y-intercept. Why didn't I see that before...
October 14, 2013

Pre-Calculus
It has been found that the supply of golf clubs varies linearly with its price. When the price per item was $ 76.00 ,32 items are supplied; When the price was $ 90.25 , 70 items are supplied. What is the lowest price above which golf clubs will be supplied ? So I know the ...
October 14, 2013

geometry
find measurement angle bac db and dc are paralell, da intersects bc, angle a is 65 degrees so i multipied by two and came up with the answer 130 degrees, is this correct? thanks
October 14, 2013

Pre-Calculus
I tried and got 3.371880575, but I think I'm still wrong...
October 9, 2013

Pre-Calculus
You are given a pair of equations, one representing a supply curve and the other representing a demand curve, where p is the unit price for x items. −p+0.0208333333333333x+2=0 and p = √(57-x) What is the market equilibrium for x? I know I'm supposed to set both...
October 9, 2013

Pre-Calculus
Actually I think you used the wrong function. The 1st one is the demand, not the second.
October 8, 2013

Pre-Calculus
You are given a pair of equations, one representing a supply curve and the other representing a demand curve, where p is the unit price for x items. 466p+90x−2390=0 and 484p−22x−978=0 Determine the revenue function. Revenue function R(x)=? I got (-90x/466...
October 8, 2013

Pre-Calculus
For the function f(x)=3x^3−42x Compute the difference quotient [f(x+h)−f(x)]/h,h≠0 I checked my work like 3 times and still got [(-2x^3)+(3hx^2)+(3xh^2)+(h^3)-(42h)]/h Is it wrong?
October 7, 2013

Pre-Calculus
Oh yeah I forgot it meant that P = 0 thanks
October 6, 2013

Pre-Calculus
The function is P=−11x^2+346.5x−2612.5
October 6, 2013

Pre-Calculus
The profit in dollars in producing x items of some commodity is given by the equation P=−11x2+346.5x−2612.5. How many items should be produced to break even?(If there are two break-even points, then enter the smaller value of x. Your solution may not be an integer...
October 6, 2013

Pre-Calculus
thanks I figured out what I did wrong
October 6, 2013

Pre-Calculus
Find the unknown in the following equation. If there are more than one solution, then separate the solutions with a comma. (−8y−4)^2+10=14 y=? I keep on getting y=-0.5, is that correct?
October 6, 2013

Pre-Calculus
thanks!
October 6, 2013

Pre-Calculus
The Hotel Bellville has 400 rooms. Currently the hotel is filled . The daily rental is $ 250 per room. For every $ 14 increase in rent the demand for rooms decreases by 5 rooms. Let x = the number of $ 14 increases that can be made. What should x be so as to maximize the ...
October 6, 2013

Pre-Calculus
thanks
September 30, 2013

Pre-Calculus
oh ok. But if I wanted to find how long it takes the ball to come back to the ground then I would have to factor it right?
September 30, 2013

Pre-Calculus
Sorry, the equation is −16t^2+72t+364
September 30, 2013

Pre-Calculus
A ball is thrown up at the edge of a 364 foot cliff. The ball is thrown up with an initial velocity of 72 feet per second. Its height measured in feet is given in terms of time t, measured in seconds by the equation h=−16t2+72t+364. How high will the ball go? To get how ...
September 30, 2013

Pre-Calculus
So the answer is C(x)= 2574 + 3x?
September 30, 2013

Pre-Calculus
I solved that and got C(x) = 2580 + 3x, but apparently it's still not the right answer...
September 30, 2013

Pre-Calculus
A local photocopying store advertises as follows. " We charge 14 cents per copy for 150 copies or less, 6 cents per copy for each copy over 150 but less than 230, and 3 cents per copy for each copy 230 and above. " Let x be the number of copies ordered and C(x) be ...
September 30, 2013

Pre-Calculus
Then what would the cost be for 150<x<230? I don't think there's a fixed cost for this either, but I don't think it'd be correct to write C(x) = 6x.
September 30, 2013

Pre-Calculus
A local photocopying store advertises as follows. " We charge 14 cents per copy for 150 copies or less,6 cents per copy for each copy over 150 but less than 230, and 3 cents per copy for each copy 230 and above. " Let x be the number of copies ordered and C(x) be the...
September 30, 2013

Pre-Calculus
Oh, ok, so it's not equivalent. I get it now. It is 2.2. Thanks!
September 28, 2013

Pre-Calculus
Wait, Steve, I think that what you wrote: A(t) = 11000 - (11000-10995.60)*t/4.4 is equivalent to what I wrote: A(t) = -4.4t + 11,000 but when I solve mine, why do I keep on getting 0.5 instead of 2.2?
September 28, 2013

Pre-Calculus
A machine worth $ 11000 new and having a scrap value of $ 10995.6 is to be depreciated over a 4.4 -year life. Find the function that describes straight line depreciation for this situation. At what time will the machine be worth $ 10997.8 according to this model? So I know ...
September 28, 2013

Pre-Calculus
Nevermind, I figured it out, it's $63.
September 28, 2013

Pre-Calculus
If a manufacturer has fixed costs of $ 300 , a cost per item for production of $ 60 , and expects to sell at least 100 items, how should he set the selling price to guarantee breaking even? I set up the cost function by writing 300 + 60x, but I don't know what to do next...
September 28, 2013

Math
Describe the steps for simplifying the expression 3a^3 + 4 - 4a - 2a^3 + 6 + 12a - b^3. Be specific and be sure to include the meaning of like terms in your explanation.
September 25, 2013

math
(t-r)^2(t-r)^2(t-r)^2
September 19, 2013

Financial management
how do I solve for x in the following equation: 1.2 ($1,364,994,000 + x) = $1, 807,626,000 + x
September 14, 2013

Physics
Two identical capacitors store different amounts of energy: capacitor A stores 2.5 x 10-3 J, and capacitor B stores 2.8 x 10-4 J. The voltage across the plates of capacitor B is 11 V. Find the voltage across the plates of capacitor A.
September 12, 2013

physics
A catapult launches a test rocket vertically upward from a well, giving the rocket an initial speed of 79.0 m/s at ground level. The engines then fire, and the rocket accelerates upward at 3.90 m/s2 until it reaches an altitude of 980 m. At that point its engines fail, and the...
August 25, 2013

MATH
Ned’s Sheds purchases building materials from Timbertown Lumber for $3,700 with terms of 4/15, n/30. The invoice is dated October 17. Ned’s decides to send in a $2,000 partial payment. By what date must the partial payment be sent to take advantage of the cash ...
August 18, 2013

Physics
An object with an initial velocity of 5 m/s has a constant acceleration of 2 m/s^2. When its speed is 15 m/s how far has it traveled?
July 24, 2013

Philosophy
Identify a current event or contemporary social issue that involves ethical values.
July 16, 2013

Chemistry
Net ionic equations for: Br- + AgNO3 CO3 + AgNO3 Cl-+ AgNO3 I + AgNO3 PO4^-3 + AgNO3 SO4^-2 + AgNO3 S^-2 + AgNO3 They all formed ppt,but I don't know where to go from here. Even a couple to get me started would be greatly appreciated!
July 14, 2013

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