Saturday

April 30, 2016
Total # Posts: 1,396

**Calculus**

f(x)=[3x^13]e^(−7x) On which intervals is the function concave up and concave down? I know when you find the 2nd derivative, the x-values are 0, 1.34206, and 2.37222, and that the 2nd derivative > 0 at x=1.34205 and < 0 at 2.37222. How does this tell me the ...
*May 18, 2014*

**Calculus**

thanks
*May 17, 2014*

**Calculus**

The quantity Q of radioactive carbon remaining in a 200-gram wood sample at time t is given by the expression Q(t)=200e^(−0.000225⋅t). How much radioactive carbon remains in the sample after 100500 years? I just plugged in 100500 as t and got 3.02375 grams as an ...
*May 17, 2014*

**Calculus**

thanks!
*May 7, 2014*

**Calculus**

How much should be deposited into an account today if it is to accumulate to $32400 in 30 years if the account bears interest at 8.01% compounded monthly? I did A = 32400(1 + 0.0801/12)^(12*30) = $355,375, but that's wrong...
*May 7, 2014*

**Calculus**

ok thanks
*May 6, 2014*

**Calculus**

I thought it would just be A = 88e^(0.07*9), which equals 165.23 pounds, but apparently that's not correct...
*May 6, 2014*

**Calculus**

Poli 761 (a fictitious substance) decays by about 7% every day. How much of a 88 pound sample remains after 9 days?
*May 6, 2014*

**Calculus**

thank you!
*May 5, 2014*

**Calculus**

Why does 2ln6 - 2ln3 = ln4?
*May 5, 2014*

**maths**

1234567 x 7654321
*April 29, 2014*

**MATH_URGENT**

what additional information is needed to prove triangle klm triagle pqr by sas?
*April 27, 2014*

**Math**

Write the inequality and solve: The product of a number and 7 is less than 28
*April 27, 2014*

**geometry**

Hi, could someone explain to me the steps I should take to solve the following problem. If radius BE is a perpendicular bisector of chord AC, then what is AB to the nearest tenth? BD is 7cm and DC is 9.
*April 19, 2014*

**geometry**

The radius of the earth is approximately 6371 km.If the international space station (ISS) is orbiting 353 km above the earth, find the distance from the ISS to the horizon(x)
*April 16, 2014*

**geometry**

10^2=x•(x+3x) Use quadratic formula to solve
*April 15, 2014*

**Calculus**

no, but thanks for your answer!
*April 9, 2014*

**Calculus**

Evaluate ∫(2x^3/√(1-x^4))dx I can't figure out what u and du is... please help thanks
*April 9, 2014*

**Calculus**

Given f(x)=−2x^3 -3x + 1, the value of the derivative of the inverse function, f^−1(x) at x=−21 is (f^1)′(−21)= ? please explain how to solve this
*April 3, 2014*

**Calculus**

If e^x = 243 and e^y = 32 then e^((3x + 4y)/5) =? The answer is 432, but I don't understand why.
*March 27, 2014*

**Calculus**

Thank you very much!
*March 26, 2014*

**Calculus**

The height in feet above the ground of a ball thrown upwards from the top of a building is given by s=-16t^2 + 160t + 200, where t is the time in seconds. If the maximum height is 600 feet, what is v^-1(32)? The answer is supposed to be 4 seconds, but I don't understand ...
*March 26, 2014*

**algebra**

Mary has a total of $5000 invested in two accounts. One account pays 5% and the other 8%. Her interest in the first year was $331. Write and solve a system of equations to find out how much she has invested in both accounts
*March 26, 2014*

**geometry**

If I need to make a mold with a square base with a volume of exactly 28 cubic centimeters how many possible molds could I make?
*March 26, 2014*

**chemistry**

its actually my fault sorry :$ , i wrote the question wrong its barium oxide + water so would it be BaO + H2O --> Ba(OH)2 ??
*March 25, 2014*

**chemistry**

oh so for barium + water the chemical equation is BaO + H2O but how do i figure out the rest?
*March 25, 2014*

**chemistry anyone??? help!!**

help me please!! i dont get it
*March 25, 2014*

**chemistry**

what is the chemical & word equation of sulfur dioxide + water i don't understand this, can someone please explain to me how to do this!!?
*March 25, 2014*

**literacy**

thankyou Ms.Sue!! :D
*March 24, 2014*

**literacy**

can i just show u tomorrow then if u don't mind? please and thank you !! :)
*March 24, 2014*

**literacy**

its not really for a class i'm just practicing for the osslt test. so will u actually mark it and give feedback??
*March 24, 2014*

**literacy**

and also i have another question. if i write me news report will u pleasee give it a level out of 6 ??
*March 24, 2014*

**literacy**

so should it be: "a major ice storm shuts down the region of ... on january 27 2012" ??
*March 24, 2014*

**literacy**

so can my lead sentence be " on january 27 2012 a major ice storm shut down the whole region of ..." ??
*March 24, 2014*

**literacy**

how do you write a news report on the topic "storm shuts down region"??
*March 24, 2014*

**literacy**

oh okay thanks!! (:
*March 21, 2014*

**literacy - Ms. Sue???**

will u mark them and give it a level?
*March 21, 2014*

**literacy**

im in grade 10 and if i do the osslt literacy practice tests. will someone on here mark my writing tasks? i can mark the multiple choice questions on my own but i just need someone to mark the writing stuff
*March 21, 2014*

**Chemistry **

find the freezing point of a solution containing 3 grams of a compound of molar mass 125 g/mol in 45 g of camphor
*March 17, 2014*

**Chemistry**

Dissolving solid CaCl2 H2O in a large volume of water is endothermic to the extent of 14.6 kj/mol. Also given: CaCl2(s)+6H2O(l)->CaCl2* 6H2O(s) delta H = -97.0 kj what is the heat of solution of anhydrous CaCl2 in a large volume of water?
*March 17, 2014*

**Chemistry**

Dissolving solid CaCl2 H2O in a large volume of water is endothermic to the extent of 14.6 kj/mol. Also given: CaCl2(s)+6H2O(l)->CaCl2* 6H2O(s) delta H = -97.0 kj what is the heat of solution of anhydrous CaCl2 in a large volume of water?
*March 17, 2014*

**Chemistry **

What is the percent KCL by mass in a 3.00 molal solution?
*March 17, 2014*

**chemistry**

What is the percent KCL by mass in a 3.00 molal solution?
*March 17, 2014*

**math**

Center C has a radius of 13.Chord AB=10. Find the distance from the center of the circle to chord AB. CD=?
*March 15, 2014*

**geometry**

center C has a radius of 13.Chord AB=10.find the distance from the center of the circle to chord AB. CD=?
*March 15, 2014*

**geometry**

T or F two coplanar circles with two points of intersection will have four common tangents?
*March 15, 2014*

**human bio please help**

Skeletal muscles contract when their (A)__________ shorten, using the energy source ATP. A rise in the concentration of (B)__________ ions causes muscle contraction.
*March 14, 2014*

**please help bio**

From the esophagus down, the 6-9 meter long digestive tube is made up of four layers: the inner (A)__________ of epithelial cells, a sub mucosa, smooth muscle, and serosa. Nutrients from the tube are absorbed across the layers into the bloodstream. (B)__________ are circular ...
*March 13, 2014*

**biology please help**

whiich of these fit together A. lipase B. nuclease C. pancreatic amylase D. pepsin bread crumb stuffing butter mashed potatoes turkey
*March 13, 2014*

**human biology please help**

The Golgi body receives proteins from the (A) __________, "packages" those proteins and "ships" them to other areas of the cell, or to the (B) ________ for secretion.
*March 11, 2014*

**biology PLEASE HELP **

The __________ (the cell’s outer border) controls the movement of materials into and out of the cell. It is called a lipid bilayer because of the type of molecules it is made up of and it has two layers
*March 11, 2014*

**human biology need help **

The Golgi body receives proteins from the (A) __________, "packages" those proteins and "ships" them to other areas of the cell, or to the (B) ________ for secretion.
*March 11, 2014*

**Human biology please help**

Sequences of chemical reactions, called metabolic pathways, can be sped up, or catalyzed, by (A) __________ , which are made mostly of (B) ___________.
*March 11, 2014*

**Calculus**

Determine the equation of the inverse function if f(x) = 2x^2+3, and x≥0. The answer is supposed to be f^-1(x)=[√(2x-6)]/2. This is what I did: x=2y^2+3 2y^2=x-3 y^2=(x-3)/2 y=√[(x-3)/2] Did I do something wrong? Thanks!
*March 10, 2014*

**Calculus**

If f(x)= -4x^2+7 and x≤0, what is the equation of the inverse function? The answer is supposed to be f^-1(x)= -[√(7-x)]/2, but this is what I did: x=-4y^2+7 -4y^2=x-7 y^2=(x-7)/-4 y= √[(x-7)/-4] Did I do something wrong? By the way, for the original function...
*March 10, 2014*

**math**

There are eight shelves. How many soup cans a grocery clerk stack if the bottom shelf has 21 cans and each additional shelf has 2 fewer soup cans than the previous shelf?
*March 6, 2014*

**math**

using the interest formula A=P(1+r/n), solve for the indicated variable. solve for P
*March 5, 2014*

**Math**

Eric has two rock samples. One has a mass of 600 grams and the other has a mass of 1 kg. He recorded the total mass as 7 kg. What did he do wrong? What is the correct answer?
*March 4, 2014*

**College Cultural Geography**

"Respect for traditions that violate human rights is taken by Western universalism as tantamount to disrespect for their victims." What about this part?
*March 2, 2014*

**College Cultural Geography**

Can someone explain what this paragraph is talking about? I do not understand it. "But Western universalism, again, has two faces: it also promotes the principles of liberty and equality throughout the world. It is not possible to proclaim global human rights, on the one ...
*March 2, 2014*

**physics**

A 400 g marble block has a specific heat of 860 J/kg C deg. If the block is placed in 700 ml of water, the marble changes it temperature by 17 Celsius degrees. Since the specific heat of water is known to be 4186 J/kg C deg, what is the temperature change of the water. (The ...
*February 19, 2014*

**physics**

A wave travels at 575 m/sec in a dense media. The wave is observed to The length of the media is 95.8 cm. When the wave is reflected at the end, its phase is reversed (an upward motion becomes a downward motion.) What is the frequency of the resonant wave in this media?
*February 19, 2014*

**physics**

The speed of sound in air varies with the temperature and humidity of the air. In dry air at 20 degrees Celsius, the speed of sound is approximately 343 m/sec. A closed tube resonates with a node at each end for a sound wave in air. What is the length of tube you would choose ...
*February 19, 2014*

**Physics**

1200kg car moving at 9.72m/s runs into and sticks to a parked 1000kg car. The collision takes 0.15s and after the crash the cars wheels lock and they skid to a stop on the u=0.40 road. what is the distance travelled before skidding to a stop?
*February 17, 2014*

**Thesis Statement**

Weak, because you should mention specifically what is it about your experience with teaching children that you want to write about.
*February 17, 2014*

**Calculus**

Thanks so much Reiny! I never thought of adding the cost to the equation, but now I know.
*February 17, 2014*

**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*