Monday

May 4, 2015

May 4, 2015

Total # Posts: 3,990

**Statistics**

SAT scores are distributed with a mean of 1,500 and a standard deviation of 300. You are interested in estimating the average SAT score of first year students at your college. If you would like to limit the margin of error of your 95% confidence interval to 25 points, how many...
*May 2, 2015*

**Chemistry**

A flask contains 25.0 mL of diethyl ether weighth 18.74 µg (micrograms). What is the density of the diethyl ether and grams per liter? I'm not sure how to set this problem up correctly.
*May 1, 2015*

**Chemistry**

Sulfur dioxide reacts with chlorine to produce thionyl chloride and dichlorine oxide S: 32.0 amu O: 16.0 amu Cl: 35.45 amu SO2 + 2Cl2 --> SOCl2 + Cl2O If 0.400 moles of chlorine gas reacts excess sulfur dioxide, how many moles of dichlorine oxide are forme?
*May 1, 2015*

**Chemistry**

Aluminum metal reacts with iron (III) oxide to produce aluminum oxide and iron metal. Answers the following three questions note: you will need to write a balanced equation to answer them Al: 26.9 amu Fe: 55.8 amu O: 16 amu 1 How many moles of iron (III) oxide are required to ...
*May 1, 2015*

**Chemistry**

Solutions of sodium hypochlorite, NaClO are sold as bleach. They are prepared by the following reaction: 2NaOH + Cl2 --> NaCl + NaClO + H2O If you have 2.32 mol of NaOH and 2.74 mol of Cl2 ga available to react, answer the following questions Na: 23.0 amu Cl:35.5 amu O: 16....
*May 1, 2015*

**Chemistry**

A flask contains 25.0 mL of diethyl ether weighth 18.74 µg (micrograms). What is the density of the diethyl ether and grams per liter?
*May 1, 2015*

**Chemistry**

In an experiment, 13g of methanol and 11 g of carbon monoxide were placed in a reaction vessel. Given the following reaction C:12.0 amu O:16.0 amu H:1.0 amu CH3OH + CO --> HC2H3O2 1 What is the theoretical yield of acetic acid? 2 If the actual yield of acetic acid is 19.1 g...
*May 1, 2015*

**Chemistry**

How can you write this formula? I'm stuck
*May 1, 2015*

**Chemistry**

A mixture containing 11.9 g of calcium fluoride and 10.3 g of sulfuric acid is heated to drive off hydrogen fluorid. Given the following reaction what is the me maximum number of grams of hydrogen fluoride that can be obtied? Ca: 40.0 amu F: 19.0 amu H: 1.0 amu S 32.0 amu CaF2...
*May 1, 2015*

**Chemistry**

Molarity What is the final volume (in Liters) of a solution prepared by diluting 25 mL of 8.25 M sodium hydroxide to a concentration of 2.40 M?
*May 1, 2015*

**Chemistry**

An organic compound consists of only carbon, hydrogen, and oxygen. Through combustion analysis, 5.671g of water and 36.933g of carbon dioxide are formed from 17.422g of sample. C:12.0 amu O: 16.0 amu H:1.0 amu In the space provided please write the empirical formula and, if ...
*May 1, 2015*

**chemistry**

Calculate the mass of oxygen gas required to occupy a volume of 6 L at a pressure of 20.9 kPa and a temperature of 37◦C.
*April 30, 2015*

**Calculus**

What is the solution to the following system of equations -2x+3y+z=5 x+5y+2z=17 To do this, I used elementary operations and isolated x to get 13y+5z=37. Is that correct so far? How would I continue?
*April 30, 2015*

**Calculus**

How would I find the equilibrant of three vectors? I am given a graph of three different vectors which meet at the point (0,0)
*April 30, 2015*

**Calculus**

If 3(a,3,2)-2(3,b,b)=(-3,1,-2) determine a and b. Describe the set spanned by the vectors. I don't know how to answer this
*April 30, 2015*

**Solved?**

I found the derivative of y=3x-1 which is y=3. Then I had the two differentiated equations equal one another: 2x+3=3 and solve for x: x=0 Then I subbed x into f(x)=x^2+3x+2 and got y=2 So the coordinate is (0,2)?
*April 30, 2015*

**Calculus**

What are the coordinates of the point on the graph of f(x)=(x+1)(x+2) at which the tangent is parallel to the line with equation 3x-y-1=0? a)(-3,2) b)(-1,0) c)(0,2) d)(1,6) To answer this, I put f(x)=(x+1)(x+2) into the form f(x)=x^2+3x+2 and found the derivative which is f&#...
*April 30, 2015*

**Calculus**

What does it mean to span in R2? I have this question: Which of the following sets if vectors span R2? a) {(1,1),(-2,-2)} b) {(1,1),(1,2)} c) {(1,2),(1/2,2)} d) {(-1,1),(1,-1)}
*April 29, 2015*

**Calculus**

Thanks! I was overthinking the question
*April 29, 2015*

**Calculus**

An airplane is heading due east with an airspeed of 220km/h when it encounters a wind from the south at 76km/h. What is the direction of the resultant velocity of the airplane The answer is E19.06°N but I don't know how
*April 29, 2015*

**SOLVED**

I made a mistake... i figured it out
*April 29, 2015*

**calculus**

For the function f(x)=x^3e^x, determine intervals of increase and decrease and the absolute minimum value of f(x) To do this I found the derivative which is f'(x)=3x^2e^x. Then I set it to zero: f'(x)=0 0=3x^2e^x How would I isolate x? And when I do, I would sub that x...
*April 29, 2015*

**Calculus**

Can you please explain how I would solve these questions? 1) Which point is 2 units from the line 12x-9y-5=0? a)(8,3) b)(7/6, -7/3) c)(14,6) d)(1,1) 2.) Which of the following sets of vectors spans R2: a) {(1,1),(-2,-2)} b) {(1,1),(1,2)} c) {(1,2),(1/2,2)} d) {(-1,1),(1,-1)}
*April 29, 2015*

**Calculus**

Susan pulls on a rope sleigh with a force of 120 N. If the rope makes an angle of 25 degrees with the horizontal, what is the force that tends to lift the sleigh? a)120.00 N b)108.76 N c)50.71 N d)84.85 N how would you know?
*April 28, 2015*

**Help**

What are some things you can skip?
*April 28, 2015*

**Calculus**

How would I find the second derivative if f(x)= √(x^3+2) using the quotient rule. I got to the step where [(12x√(x^3+2))-(9x^4/√(x^3+2))]/4(x^3+2) how would i go from that to: (3x(x^3+8))/(4(x^3+2)^3/2)
*April 27, 2015*

**critical numbers**

thanks!
*April 27, 2015*

**critical numbers**

How would I find the critical numbers of f'(x)=(x-3)^3(x+4)(x^2+1)? The answer is x=-4, x=3
*April 27, 2015*

**English**

What does Georgiana represent in "The Birthmark"? feminine perfection<----- evil and greed the rewards of hard work the price of madness
*April 24, 2015*

**AP CHEM**

The pKa of acetic acid is 4.74. What is the buffering range of this acid and its conjugate base? Explain.
*April 22, 2015*

**Laboratory Chemistry **

The activity of a stock isotope is 10,000 DPM/0.10mL. If 0.25 ml of this stock is placed in 2.50 ml of water, what is the activity in the diluted specimen? My guess is that I just multiply the 10,000 DPM by the 1/10 dilution factor. I then come up with 1,000DPM/0.10ml. Does ...
*April 20, 2015*

**Vectors**

correction, the two planes are coincident that the other intersects in line
*April 19, 2015*

**Vectors**

What is the nature of intersection of these three planes: 5x+3y-z=11 -2x-7y+10z=2 6x+21y-30z=-6 I know that the answer is two parallel planes and the other one intersecting in a line. my question is how would you know that the first equation intersects in a line? Would you use...
*April 19, 2015*

**Vectors**

Determine the vector equation of a plane that contains the line with symmetric equation (x+3)/-2=(y+1)/5=(z+2)/4 and the point P(1,3,0). For this question to find the direction vector you would use subtraction with the points (-3,-1,-2) and (1,3,0). Why would it be (1,3,0)-(-3...
*April 19, 2015*

**Vectors**

At what point does the line r=(-2,3,1)+s(2,3,-1) intersect the y-axis?
*April 18, 2015*

**Vectors**

thanks!
*April 17, 2015*

**Vectors**

What is the distance between the parallel lines having equations 2x+2y=16 and x+y=0? I'm getting 2 as my answer but the answer is supposed to be 4√2
*April 17, 2015*

**Vectors**

why does this equation 3xy +y = 0 represent two planes?
*April 17, 2015*

**Project help please!!**

but I don't know how to make it into a video/commercial :(
*April 16, 2015*

**Project help please!!**

I have to come up with a product (such as soap, face cream, shampoo, cleaning spray, etc) and make a commercial for it. and I have to make up a name for it and the stuff that's found in it. I can't think of any products, I was thinking a shampoo commercial but I don&#...
*April 16, 2015*

**calc**

If f(x) = 3x^2 − 2x, 0 ≤ x ≤ 3, evaluate the Riemann sum with n = 6, taking the sample points to be right endpoints.
*April 16, 2015*

**socials**

We're the sons of liberty justified in their treatment of the loyalists
*April 15, 2015*

**Vectors**

How would I convert cartesian equation to parametric? For example: 2x-y+3z-6=0
*April 14, 2015*

**calc**

A boat leaves a dock at 3:00 PM and travels due south at a speed of 20 km/h. Another boat has been heading due east at 15 km/h and reaches the same dock at 4:00 PM. How many minutes after 3:00 PM were the two boats closest together? (Round your answer to the nearest minute.)
*April 14, 2015*

**Math**

Some number added to -12 is 45. Add this number to 30. Multiply the answer by 3. What is the final number?
*April 14, 2015*

**Science**

What does the electron shell rotate around?
*April 13, 2015*

**Vectors**

How are these two lines coincident? 1) r=(1,7)+s(2,5) 2) x=4t+3 y=10t+12
*April 12, 2015*

**business math**

Jen purchased a condo in Naples Florida for $699,000. She put 20% down and financed the rest at 5% for 35years. What are Jens total finance charge?
*April 12, 2015*

**algebra**

Factor: X^4 y-y^5
*April 11, 2015*

**math**

an airplane is flying 120 km south and 130km west of an airport. It is flying at a height of 10 km . what is the straight line distance to the airport?
*April 10, 2015*

**linear algebra urgent**

^ each of those 3 sets are vectors
*April 9, 2015*

**linear algebra urgent**

Use the Gram-Schmidt process to transform the basis 1 1 1 , 0 1 1 , 2 4 3 for the Euclidean space R3 into an orthonormal basis for R3.
*April 9, 2015*

**Social Studies**

The revolutionary war was fought on american soil. how do you think this fact influenced the role of women in war?
*April 9, 2015*

**linear**

Let W be the subspace of R5 spanned by the vectors w1, w2, w3, w4, w5, where w1 = 2 −1 1 2 0 , w2 = 1 2 0 1 −2 , w3 = 4 3 1 4 −4 , w4 = 3 1 2 −1 1 , w5 = 2 −1 2 −2 3 . Find a basis for W ⊥.
*April 9, 2015*

**Ib math**

The marks of 2376 students in an IB exam are normally distributed with mean 49 marks and variance 225 A) if the mark is 45 estimate the number of candidates who passed the exam? B) if top 7% of students are awarded a 7, find the minimum mark required to obtain a 7? mean=49 ...
*April 9, 2015*

**World History**

Thanks
*April 6, 2015*

**World History**

could you please explain what i'm suppose to do and give me some websites i can get information from.
*April 6, 2015*

**World History**

I need help. In a brief essay, explain three ways in which the Roman Catholic Church responded to the spread of Protestantism in the sixteenth century. Describe each part of the church’s response using specific facts.
*April 6, 2015*

**astronomy**

^ and any number or combination of those can be chosen.
*April 5, 2015*

**astronomy**

Even though I do not believe the Big Bang is what created the universe(although what people clam the bing bang was would have been similar to what happened when God said "Let there be light" I still have astronomy hw. haha. I am having trouble with this question. The...
*April 5, 2015*

**linear algebra check**

Use the Gram-Schmidt process to transform the basis [1 1 1] , [0 1 1] , [2 4 3] for the Euclidean space R3 into an orthonormal basis for R3. (Enter each vector in the form [x1, x2, ...]. Enter your answers as a comma-separated list.) so i went through the process and got [1/...
*April 4, 2015*

**calc**

how did you expand the determiannt
*April 2, 2015*

**calc**

If possible, find a, b, and c so that v = [a b c] is orthogonal to both w = [1 6 1] and x = [1 −9 1]
*April 2, 2015*

**engr**

what useful product can you make using recyclable items?
*April 1, 2015*

**AP Chemistry**

A 5.0 M solution of HNO3 is titrated with 0.3 M NaOH. Identify the species that have the highest concenttrations in the solution being titrated halfway to the equivalence point. A 25.15 ml of 0.35 m HNO3 was titrated with an unknown concentration of NaOH. The endpoint was ...
*March 29, 2015*

**math check**

determine whether the given vector A in M22 belongs to the span (a1,a2,a3) where a1=[1 -1; 0 3] a2=[1 1; 0 2] a3=[2 2; -1 1] and A=[5 1; -1 9] so I set up an augmented matrix , but im not sure if I set it up correctly. I made a1 a2 and a3 into columns. 1 1 2 | 5 0 0 -1 | -1 -1...
*March 28, 2015*

**AP Chemistry**

A buffered solution was created by mixing solutions of NH4Cl and NH3 at 25 C. Which species, NH4+ or NH3, has the highest concentration in this buffered solution?. Justify your answer.
*March 26, 2015*

**accounting**

If a business is purchased by the issue of 10000 $10 8% debentures trading at $95, how much is the purchase consideration? I did 10000x95, but the answer in the key is option D instead, 95000, not 950,000... I'm totally confused..
*March 25, 2015*

**Math.**

Half of Allan's test score plus eight equals 50. What did Allen score on his test?
*March 24, 2015*

**math**

When the equation of a line is written in general form, Describe the Slope of the line when A=0 or and B=0 ? Thanks!
*March 24, 2015*

**math**

Verify that the function satisfies the three hypotheses of Rolle's Theorem on the given interval. Then find all numbers c that satisfy the conclusion of Rolle's Theorem. (Enter your answers as a comma-separated list.) f(x) = 5 − 6x + 3x2, [0, 2] can someone ...
*March 23, 2015*

**Vectors**

How would I find the direction vector parallel to a line? For example, how is (2,1) a direction vector parallel to the line -x+2y-10=0
*March 20, 2015*

**Vectors**

determine the number of solutions, the generalized parametric solution, and explain why there are no integer solutions for the equation 2x+10y=31
*March 17, 2015*

**Vectors**

Can you please explain how to answer this? What is a solution for the following system? x-4y+z=2 and -x+4y-2z=8 a) x=4s+12, y=s, z=-10 b) x=s+4, y=3s, z=-4 c) x=2s+5, y=s, z=-12 d) x=s, y=4s, z=-12
*March 17, 2015*

**Vectors**

Multiple choice: Can you please explain how to answer this? Which point does not lie on the same plane as the points P(1,5,6), Q(-2,-3,4) and R(-1,3,2) a) S(0,4,4) b) S(4,13,8) c) S(0,-1,8) d) S(1,-3,2)
*March 17, 2015*

**Vectors**

What is the distance between the parallel lines having equations 2x+2y=16 and x+y=0 a) 16 b) 4 root 2 c) 2 d) 8 I got the answer 2. I solved for y in the 2x+2y=16 equation and got 8. that gave me point (0,8) I used the d= (ax+by+c)/root (a^2+b^2) using the equation x+y=0 and ...
*March 17, 2015*

**Vectors**

To answer this I would just sub in the x and y values right? I got a) as my answer since it equals 0. Which of the following would describe the sketch of the expression xy+2y-3x-6=0 a) the planes x=-2 and y=3 b) the planes x=3 and y=-2 c) the planes x=6 and y=2 d) the planes x...
*March 17, 2015*

**Vectors**

can you please explain how to answer this: Which of the following is not a plane a) r=(1,3,4)+s(2,-1,2)+t(1,1,1), s,t∈R b) r=(2,4,2)+s(1,-2,3)+t(3,2,2), s,t∈R c) r=(3,2,3)+s(4,-4,2)+t(-2,2,-1), s,t∈R d) r=(-2,1,4)+s(2,2,-1)+t(2,2,1), s,t∈R
*March 17, 2015*

**Vectors **

The shortest distance between a point and a line occurs at: a) infinitely many points b) one unique point c) random points d) a finite number of points
*March 17, 2015*

**Vectors**

Multiple choice. How would I answer this in a short way? what is the distance between the skew lines L1:(0,4,-3)+s(-1,1,3),seR and L2: (1,2,5)+t(-3,2,5),teR? a) 4 root 2 b) 7/2 c) root 2 d) (7 root 2)/2
*March 17, 2015*

**Vectors**

no clue how to answer it. I put each slope into the y=mx+b formula and found the b values, but i'm not sure if i'm supposed to do that
*March 16, 2015*

**Vectors**

Two lines with the slopes m1=4/3 and m2=-7/2 intersect at (3,4). Determine the equations of the two lines and check your answer by solving them
*March 16, 2015*

**Vectors**

would the answer be r-(3,2,-1)+s(1,1,1)
*March 16, 2015*

**Vectors**

Determine the vector equation of a line passing through the point P(3,2,-1) and with a direction vector perpendicular to the line r=(2,-3,4)+s(1,1,-2), seR
*March 16, 2015*

**Calculus**

Determine the slope of the tangent to the function f(x)=5e^x - 2e^(2x) at the point with x-coordinate x=1
*March 16, 2015*

**math**

How would I write the equation y=3.9657(0.9982^x) in the format of g(x)=f(x)+f(x-60)?
*March 14, 2015*

**Calculus**

Find an equation of a line tangent to y = 2sin x whose slope is a maximum value in the interval (0, 2π] I believe the equation is y=2x-4pi. How is the b-value -4pi?
*March 14, 2015*

**Vectors **

Explain why the planes 3x-6y-9z+5=0 and x+2=2y+3z never intersect
*March 14, 2015*

**Vectors**

Does the point of intersection between L1:(4,9,2)+s(1,-1,-1), seR and Ls: (2,11,4)+t(5,-3,-4), teR lie on the plane 3x-2y+3z+4=0?
*March 14, 2015*

**math**

How would I solve this equation for x? 0=3.9657(0.9982^x)ln0.9982
*March 14, 2015*

**Calculus**

How would I find the instantaneous rate of change using this formula y=3.9657(0.9982^x) and given a table of values?
*March 13, 2015*

**Swakop High**

John has $6000 to invest. He invests part of it at 5% and the rest at 8%.How much should be invested at each rate to yield 6% on the total amount?
*March 13, 2015*

**Vectors**

would it be d?
*March 11, 2015*

**Vectors**

which is not a possible type of intersection between three planes? a) intersection at a point b) three coincident planes c) intersection along a line d) intersection along a line segment I know that planes can intersect in a line but I don't know which of c and d would be ...
*March 11, 2015*

**Math**

Explain how the order of operations determines how you simplify a numeric expression. explain the rules for addition, subtraction, multiplication, division, and the use of grouping symbols.
*March 10, 2015*

**College Algebra **

John invested his savings in two investment funds. The $12,000 that he invested in Fund A returned a 3% profit. The amount that he invested in Fund B returned a 10% profit. How much did he invest in Fund B, if both funds together returned a 6% profit?
*March 10, 2015*

**Vectors**

Also, R(-9,18) lies on the line
*March 9, 2015*

**Vectors**

How would you write a vector equation for a line using parametric equations? For example: A line is defined by x=-2-t and y=4+2t,teR. a) Write a vector equation for this line using parametric equations. b) write a second vector equation different from the first
*March 9, 2015*

**Calculus**

For the question "Determine the equation of the tangent to the curve y = xtanx at the point with x-coordinate π." how is the answer -πx + y + π2 = 0?
*March 9, 2015*

**calc**

At noon, ship A is 150 km west of ship B. Ship A is sailing east at 35 km/h and ship B is sailing north at 30 km/h. How fast is the distance between the ships changing at 4:00 PM?
*March 9, 2015*