Wednesday

May 27, 2015

May 27, 2015

Total # Posts: 253

**trig**

Prove: sin(x–y)sin(x+y)=sin^2(x)–sin^2(y)
*March 26, 2012*

**Chemistry**

Given the following equation: Na2O + H2O ---> 2 NaOH. How many grams of NaOH is produced from 1.20 x 10^2 grams of Na2O? How many grams of NaO2 are required to produce 1.60 x 10^2 grams of NaOH?
*March 21, 2012*

**chemistry**

A plastic container with a mass of 30 grams gains 1,140 joules of heat. If the temperature of the container increases 20°C, what is the specific heat of the plastic in the container?
*January 4, 2012*

**smu**

In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five test vehicles of each type were crashed, with the results shown below. Research question: Are the mean crash damages the same for...
*December 19, 2011*

**SMU**

A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with a standard deviation of $3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was $5.12 with a standard ...
*December 19, 2011*

**Trig**

In ABC, vertex C is a right angle. Which trigonometric ratio has the same trigonometric value as Sin A? A Sin B B Cosine A C Cosine B D Tan A
*December 13, 2011*

**Trig**

Which trigonometric function can equal or be greater than 1.000? A Sine B Cosine C Tangent D none of the above
*December 13, 2011*

**Chemistry (PLEASE HELP ME)**

the answer in number 1 is b
*October 13, 2011*

**calculus**

What is the length of the blue line labeled r in the image below? Give your answer in terms of a and b. blue line labeled r starting at the origin and ending at a point a,b b|------------| | /| | / | | / | | / | | / | | r / | | / | | / | | / | | / | | / | _|____________|a
*September 28, 2011*

**MATH**

how do you wite an equation for the function in a problem like 4x+y=-10?
*September 18, 2011*

**math algerbra 1**

how do you solve for the function in a problem like 4x+y=-10?
*September 18, 2011*

**math**

solve the equation by factoring. 3x(x-5)=6x^2-16x
*September 10, 2011*

**algebra**

Does the function y = 2^x ever cross the x-axis? Explain why or why not
*August 17, 2011*

**algebra**

any help would be greatly appreciated :)
*August 17, 2011*

**algebra**

A boat can travel 114 miles upstream in the same time that it can travel 186 miles downstream. If the speed of the current is 6 miles per hour, find the speed of the boat without a current.
*August 17, 2011*

**statistics**

3. A researcher is interested in comparing the Christian maturity level of students who volunteer for community service versus those who do not. The researcher assumes that those who perform community service will have higher Christian maturity scores. The maturity scores tend...
*June 20, 2011*

**statistics**

2. A teacher wants to investigate whether there is a difference between male and female students in the amount of time they spend studying for statistics. The table below shows the amount of time students spend studying statistics each week. The amounts of time spent studying ...
*June 15, 2011*

**statistics**

3. A researcher is interested in whether listening to music helps or hinders test-performance. To control for differences in cognitive level, this researcher decides to use a within-participants design. He selects a random sample of participants and has them study different ...
*June 15, 2011*

**statistics**

2. A teacher wants to investigate whether there is a difference between male and female students in the amount of time they spend studying for statistics. The table below shows the amount of time students spend studying statistics each week. The amounts of time spent studying ...
*June 15, 2011*

**statistics**

1. An LU professor is interested in whether there is a difference between undergraduate students and graduate students in the amount of time spent praying each day. The professor gathers information from random samples of undergraduate and graduate students on the LU campus. ...
*June 15, 2011*

**statistics**

1. A researcher is interested in whether students who attend private high schools have higher average SAT Scores than students in the general population. A random sample of 90 students at a private high school is tested and and a mean SAT score of 1030 is obtained. The average...
*June 8, 2011*

**statistics**

6. In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their current stress level on a scale of 1 to 10. The table shows the survey results. Using a web-calculator, obtain the appropriate correlation coefficients. Number...
*June 2, 2011*

**MATH**

How would you go about finding x and y?? [x-8 2 2y] [9x-16 2 6] [ 2 -7x 7] = [ 2 -7 7] [-4 y-4 2] [-4 -1 2]
*May 10, 2011*

**trig**

How would you go about finding x and y?? [x-8 2 2y] [9x-16 2 6] [ 2 -7x 7] = [ 2 -7 7] [-4 y-4 2] [-4 -1 2]
*May 10, 2011*

**Chemistry**

1How would each of the following affect the accuracy of the calculated neutralizing power of antaid (too high, too low, no effect) explain a)The actacid tablet was not cut exactly in half before weighing b)The solution mixture of reacted antacid and excess HCL spattered out of...
*April 26, 2011*

**I need help to unscramble these words in spanish**

oaincooEdm arAilulq incEle asertdarccteoipPr erIoscrdapm loEcernoict lpaLaeliuc mroipliEeltbe
*April 26, 2011*

**Math 11th Grade**

Use Demoivre's Theorem to find the fourth roots of -16. Leave the four roots in trigonometric form. How the heck do i do this?
*April 3, 2011*

**Math**

since they have the same y value, the line is vertical. So there is no y in the equation. The equation could be A= (any# except 0)x and thats it.
*April 3, 2011*

**Math**

how do i write that in terms of An? like An= (2)^n(-1)^n some thing like that? or is that right
*April 3, 2011*

**Math**

What is the equation for the sequence 1, 2, 1/4, 8, 1/16, 32,......
*April 3, 2011*

**math**

b = 20 + 1/2(t-1975) kg/person I think thats right/my guess, no promises =]
*April 3, 2011*

**Precalc**

What name is given to figures (wave) to indicate that points are attracted to only certain regions in the plane and no to others?
*March 16, 2011*

**Chemistry**

You are titrating 35.00 mL of a 1.20 M solution of HCOOH with a strong base. If you add 1.00 mL of a 3.60 M solution of sodium hydroxide, what is the final pH of the acid solution? The Ka for HCOOH is 1.8 X 10-4.
*February 24, 2011*

**Chemistry**

Thank You so much! I really appreciate the help!
*February 23, 2011*

**Chemistry**

What is the pH of a 0.94 M solution of HBrO that is also 0.59 M in magnesium hypobromite, the salt of it's conjugate base? The Ka for HBrO = 2.8 X 10-9.
*February 23, 2011*

**Physics**

image5.65.jpg
*February 23, 2011*

**Physics**

When a patient’s injured neck is healing, it is often desirable to prevent the weight of the head from pushing down on the neck. This can be accomplished with the system of pulleys shown in the figure. The pulleys are all small and extremely light in weight and have no ...
*February 23, 2011*

**math**

Venus begins a new year every 225 days. Earth begins a new year every 365 days. If both planets begin a new year on the same day, how many days will pass befor that happens again.
*February 13, 2011*

**math**

Venus begins a new year every 225 days. Earth begins a new year every 365 days. If both planets begin a new year on the same day, how many days will pass befor that happens again.
*February 12, 2011*

**math**

3-2x+4=21
*January 27, 2011*

**ENGLISH**

Testcles
*January 13, 2011*

**Math (URGENT)**

write a formula that gives you the number of regions formed when x points are placed on a circle and all possible chords are drawn. ex. 2pts has 2 regions, 3pts has 4 regions, 5pts has 17 regions
*January 6, 2011*

**Math**

write a formula that gives you the number of regions formed when x points are placed on a circle and all possible chords are drawn. ex. 2pts has 2 regions, 3pts has 4 regions, 5pts has 17 regions
*January 6, 2011*

**geometry**

The sum of the measures of the interior angles in a polygon is 540 degrees. How many sides does the polygon have?
*December 13, 2010*

**math**

One of your friends is heading north for the Christmas holiday and the other friend is heading south. If their destinies are 1029 miles apart and one car is traveling at 45 miles per hour and the other car is traveling at 53 miles per hour. How many hours before the two cars ...
*December 3, 2010*

** world lit**

Which word did not originate from those used in various occupation? 1.seasons 2.person 3.tease 4.broker
*December 1, 2010*

**vocabulary skills**

which greek base means eye? 1.neur 2.myel 3.phren 4.ophthalm
*November 22, 2010*

**vocabulary skills**

the greek combining form -pathy means: 1.abnormal discharge. 2.tumor arising in or composed of. 3.disease of. 4.treatment of.
*November 22, 2010*

**lit **

which word is not derived from terms used in drama? 1.chorus 2.pants 3.scene 4.size
*November 22, 2010*

**Physics**

1.) A lawnmower engine claims to provide 18 hp of power and 6.25 ft lb of torque. If this is true, what must be the rotational speed in RPM? 2.) The conversion of the shaft power of a wind turbine to electricity is the function of the generator. Assume it has an efficiency of ...
*November 22, 2010*

**Physics**

A cylinder with a valve at the bottom is filled with an ideal gas. The valve is now opened and some of the gas escapes slowly. The valve is then closed, after which the piston is observed to be at a lower position. Assume that the system is in thermal equilibrium with the ...
*November 21, 2010*

**greek vocab.**

which word did not originate from the word of the arts? 1. maudlin 2. martyr 3. character 4. colossal
*November 19, 2010*

**lit **

which word did not originate from military language? 1 pioneer 2 phrase 3 salary 4 trophy
*November 19, 2010*

**Chemistry**

yes Im sorry, it was for M
*November 8, 2010*

**Chemistry**

How do I set up my equation to determine what the pH will be when the concentration of Fe^3+ is reduced to 10^-7? The previous part of the question had me find what the pH would be for the Fe(OH)3 to precipitate at 0.20 M. which i found was 1.37
*November 8, 2010*

**Calculus**

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 4 units per second. Find the rate of change of the distance from the particle to the origin at this instant.
*October 26, 2010*

**Calculus**

Gravel is being dumped from a conveyor belt at a rate of 50 cubic feet per minute. It forms a pile in the shape of a right circular cone whose base diameter and height are always equal to each other. How fast is the height of the pile increasing when the pile is 14 feet high...
*October 26, 2010*

**Social Studies**

Mummification Process
*October 25, 2010*

**social studies**

beeswax
*October 25, 2010*

**St. Andrews**

An airplane traveling 1011 m above the ocean at 145 km/h is going to drop a box of supplies to shipwrecked victims below. (a) How many seconds before the plane is directly overhead should the box be dropped? 1 s (b) What is the horizontal distance between the plane and the ...
*October 24, 2010*

**Math**

How do you write an expression for... the value in cents of 5 quarters? Thank You
*September 1, 2010*

**science**

the amount of solar energy that is intercepted by the earth is___by the __ of __. a) determind, lenght , daylight b) affected, presence, clouds in the sky c) influenced, phenomena, day and night d) influenced, phenomena, parallelism of axis e) all of the above
*August 16, 2010*

**science**

the amount of solar energy trhat is intercepted by the earth is___by the __ of __. a) determind, lenght , daylight b) affected, presence, clouds in the sky c) influenced, phenomena, day and night d) influenced, phenomena, parallelism of axis e) all of the above
*August 16, 2010*

**scinece**

an earth satellite in an elliptical orbit moves with a) faster speed as it age b) none of the above c) constant speed d) slower speed as it age
*August 16, 2010*

**science**

Geocentric" means that the earth is the center of the unvierse, including the sun, the moon, the planets, and all the stars. Is the universe geocentric? yes no yes
*August 16, 2010*

**algebra**

How would you explain to your friend why the quotient of x^8 and X^2 is x^6 and not x^4?
*August 9, 2010*

**science**

does light have mass?
*July 22, 2010*

**Chemistry II**

1.18X10^10
*April 28, 2010*

**Chemistry II**

This is what I have. Could you please correct my work? Thank you. Compute the equilibrium constant for Ni^2+ (aq) and Cd (s). reduction Ni²⁺(aq) + 2 e⁻ ⇌ Ni(s) ; E°_red = -0.25V -oxidation Cd(s) ⇌ Cd²⁺(aq) + 2 e⁻ ; E°_ox...
*April 28, 2010*

**english**

B The boys contemplated climbing up the sinister cliff but decided it was too dangerous. Contemplated means to "think through" and sinister is the equivalent of unfavorable
*April 27, 2010*

**Chemistry II**

What am I doing wrong? I am trying to balance the equation: NO3^-(aq)+Sn^2+(aq)-->Sn^4+(aq)+NO(g) here are the coefficients I have. what is wrong with them? 2NO3^-(aq)+3Sn^2+(aq)+8OH-(aq)-->3Sn^4+(aq)+2NO(g)+4H2O(l)
*April 27, 2010*

**Chemistry II**

I cannot balance this equation and I am really struggling. Cr2O7^2-(aq)+ Cu^+(s)-->Cr^3+(aq)+Cu^2+(aq) How do I get the charges to balance?
*April 27, 2010*

**Healthcare**

Healthcare expenses can cause people to lose their homes, default on loans and (in general) cause people to stop contributing to the economy because they are unable to afford basic necessities. Advantages -healtcare for people without insurance -slows the increasing cost of ...
*April 27, 2010*

**Chemistry II**

*sorry 1.17*10^-3 is what i meant
*April 27, 2010*

**Chemistry II**

Compute the equilibrium constant for Ni^2+ (aq) and Cd (s). I keep getting 1.7*10^-3 but apparently that is wrong. What am I doing incorrectly?
*April 27, 2010*

**Chemistry**

Ni (s) + Cd^2+(aq)-->Ni^2+(aq)+ Cd(s) MnO4^-1(aq)+ Al (s) ---> Mn^2+(aq)+Al^3+(aq) no matter what i do, i can't seem to balance either of these redox reactions. i'm always off. is there a trick to doing these? i need help please.
*April 25, 2010*

**Physics**

You can get a sunburn on a cloudy day, but you can't get a sunburn even on a sunny day if you are behind glass. why?
*March 30, 2010*

**Math**

Hockey teams recueve 2 points when they win and 1 point when they tie. One season, a team won a championship with 66 points. They won 12 more games than they tied. How many winds dd the team have and how many ties?
*March 21, 2010*

**Strategies!**

How could I solve this problem two ways other then using the traditional algorithm. 452+721+908
*March 14, 2010*

**7th grade**

-2a-3(b-4a) . -2b-3b-12a 10a-3b
*January 7, 2010*

**Math**

Is it like y=1/8-8 . How did you get 125
*January 7, 2010*

**Math**

Which slope would be steeper : 8 or 1/8
*January 7, 2010*

**Physics**

ok so i see what i did wrong and got a value of 2276308.355 J
*December 7, 2009*

**Physics**

A roller coaster is at the top of a 98.2 m hill and has a mass of 1831.0 kg. It is traveling at a velocity of 23.7 m/s. What is the coaster car's TOTAL energy? I took the eg=1/2mv^2 and plugged in (1831)(9.8)(98.2) and got 1762081.16 I then took the ek= 1/2mv^2 and plugged...
*December 7, 2009*

**Physics**

I dont know where to begin with this one because I dont recall my teacher giving us a formula for it. A baby carriage is sitting at the top of a hill that is 22.1 m high. The carriage with the baby weighs 15.8 N. What is the Ep for the carriage and baby in relation to the ...
*December 7, 2009*

**Physics**

well my teacher does not require that and when we went over problems similar to this, it was expanded out the way i have it now.
*December 7, 2009*

**Physics**

I just wanna check if i am right. A car is traveling with a velocity of 42.3 m/s and has a mass of 2183.0 kg. Find the Ek of the car. i used the ek=1/2mv^2 and plugged everything in to get a total of 1953010.035 J .. is that right?
*December 7, 2009*

**Calculus**

Use the table of values to estimate ⌠6 ⎮ f(x)⋅dx ⌡0 Use three sub intervals and the (a) left endpoints, (b) right endpoints, and (c) midpoints. If f is an increasing function, how does each estimate compare with the actual value? Explain your reasoning...
*November 9, 2009*

**Calculus**

Give an example of a function that is integrable on the interval [-1,1], but not continuous on [-1,1].
*November 9, 2009*

**pre-calculus**

List the possible rational roots of each equation. Then determine the rational roots. 6x^4+35x^3-x^2-7x-1 The answer in the back of the book is: -1/3 and 1/2 I know that I'm supposed to use Descartes rule of signs. I found that there was 1 positive zero and 3 or 1 negative...
*October 25, 2009*

**Statistics**

show me how
*August 31, 2009*

**Trigonometry**

9x^4-24x^3+16x^2 (Find all solutions!)
*August 12, 2009*

**algebra 2**

teresa and julia are among 10 students who have applied for a trip to washington DC. Two students from the group will be selected at random for the trip. What is the probability that teresa and julia will be the 2 students selected /
*April 23, 2009*

**math**

how do you find the area of a circle
*April 3, 2009*

**math**

how do you divide fractions
*April 3, 2009*

**11th grade Algebra II**

teresa and julia are among 10 students who have applied for a trip to washington DC. Two students from the group will be selected at random for the trip. What is the probability that teresa and julia will be the 2 students selected?
*March 31, 2009*

**algebra**

Solve the problem. Frank can type a report in 3 hours and James takes 4 hours. How long will it take the two of them typing together?
*March 20, 2009*

**5th**

what are facts and inferences please give an example
*March 19, 2009*

**sience**

Whats the best site to go on if you want to learn about the elements?
*March 19, 2009*

**language arts**

what are facts and inferences please give an example
*March 19, 2009*