tan60=2 tan30/1-tan^2 30 sqrt(3)=I'm confused of that 2 but i guess it means to multiply. again.. sqrt(3)= (2) sqrt(3)/3 / 1- sqrt(3)/2 ^2 now i dont know how to square tan . if u can show me in details i would appreciate it. this is just a practice problem and i want to ...
December 30, 2010
Hi, I'm wondering if any of you could lead me to the mark scheme for the IGCSE French Reading and Directed Writing Paper 23 May/June 2010? Any help would be appreciated. Thank you.
December 21, 2010
In jar 1, 1/8 of the marbles are white. In jar 2, 1/10 of the marbles are white. Since the jars are filled with an equal amount of marbles, take this value to be x. Therefore, x/8 + x/10 should equal to 90, the total number of white marbles. From this, we get x = 400 marbles ...
December 17, 2010
A bungee jumper of mass 60 kg jumps from a bridge tied to an elastic rope which becomes taut after he falls 10 m. Consider the jumper when he has fallen another 10 m and is travelling at 15 m/s. Work out how much energy is stored in the rope. Take g=10 m/s^2 and ignore air ...
December 17, 2010
At t = 0, a 785 g mass at rest on the end of a horizontal spring (k = 125 N/m) is struck by a hammer, which gives the mass an initial speed of 2.70 m/s. (a) Determine the period of the motion. T= .4979201367s Determine the frequency of the motion. f= 2.008354 Hz (b) Determine ...
December 7, 2010
you used a pencil to mark the chromatography paper since the carbon in the "lead" pencil does not dissolve in the solute. why does carbon not dissolve? what type of pen (ink) will also not produce a chromatogram when water is used as the solovent? explain using ...
November 29, 2010
I have no idea how to construct this program. Any help is appreciated. Thank you. In a population, the birth rate is the percentage increase of the population due to births and the death rate is the percentage decrease of the population due to deaths. Write a program that ...
November 17, 2010
An undersea research chamber is spherical with an external diameter of 3.70 m. The mass of the chamber, when occupied, is 26000 kg. It is anchored to the sea bottom by a cable. What is the tension in the cable?
November 16, 2010
Assume a parcel of air on the surface with a temperature of 29 degrees Celsius with a relative humidity of 50%. If the parcel rises at what altitude should clouds form?
November 12, 2010
no typo. I tried the quadratic equation and got -.986 and 1.24. Does this mean there are no real roots (an option in the question). Also, for the question 4x^2-12x+9, is the real root (2x-3)?
November 12, 2010
Complete the sentence by writing the correct form of the word in parentheses. You may not need to change the form that is given. 1. She made her fortune in the ____ market before she became a full-time philanthropist. (security) Would the correct answer be "securities&...
November 11, 2010
You are on the right track. Be sure to use the order of operations (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction). Multiply the 8 and 15 to get 120, then multiply the 6 and 3 to get 18. That leaves 120-18, which you would simply subtract to get your ...
November 11, 2010
Alright. a. y1+y2 should be set up as follows: (x^2+3x-1)+(x-5), which equates to x^2+4x-6 You just combine the like terms. b. (x^2+3x-1)-(x-5) For this one you need to distribute the negative, to get x^2+3x-1-x+5, then combine like terms. c. (x-5)(x^2+3x-1)= x^3+3x^2-x-5x^2-...
November 11, 2010
The figures below represent the prices (in dollars) for both paper shredders and calculators. At the 0.10 level of significance, can it be concluded that the variance in price differs between the two types of machines? Paper shredders | Calculators...
November 10, 2010
what is the reaction equation when maleic anhydride is combines with granular zinc and HCl propose structures for the products you would obtain by treating fumaric acid, cinnamic acid, and butynedioic acid with zinc and HCl. write balanced equations for the reactions.
October 30, 2010
For a sample group of 22, the mean is 86 with a standard deviation of 5. What is the 90% confidence interval of the true mean of the sample? Can you please explain the steps you used to get the answer. Thanks.
October 24, 2010
chemistry another add on
c)what is the pH after the addition of 1.0 mL of 0.10 M NaOH to 15 mL of the original solutiom.... i dont really need a im pretty sure my answer is right but should i really be getting the same answer for b and c?
October 13, 2010
a titration is done with with 25.00 mL of a .1500 M HBrO solution is titrated with .1025 M NaOH. Ka for HBrO= 2.0 x10^-9. The pH of HBrO before the titration begins is approx. closest to which of the following a. 0.82 b. 4.76 c. 8.70 d 10.60 e. 13.01 the answer is b 4.76 but how?
October 11, 2010
the Ksp for CaF2 is 3.9*10-11. assuming that calcium flouride dissociates completely upon dissolving and that there are no other important equilibria affecting the solubility, calculate the solubility in pure water, of calcium floride in m/L and in g/L
October 10, 2010
^ That is just an equation, it does not even answer the question.. I don't mean to be rude but even if you know the equation you can't answer the question if you do not know how to apply it.
September 27, 2010
In the movie "The Raiders of the Lost Arc", Indiana Jones and his guide play catch with a gold idol. The idol had a volume of about 1.30 L. In order to determine whether they could really play catch with the idol, calculate the weight (in pounds) of the idol. The ...
September 13, 2010
4.Tracie invested $x at 7% and $y at 6%. Write algebraic expressions for: a.the total amount of money invested b.the interest earned at 7% in one year c.the interest earned at 6% in one year d.the total interest earned in one year
July 28, 2010
1.)Explain why ironing boards always remain parallel to the floor and can be adjusted for people of various heights. You may want to consider the following: a.)The legs of the board are built so that AD = BD and DE = DF, and ADF and BDE are straight lines as shown. b.)Which ...
July 21, 2010
A cylindrical space colony 8 km in radius and 60 km long has been proposed as living quarters for future space explorers. Such a habitat would have cities, land and lakes on the inside surface and air and clouds in the center. All this would be held in place by the rotation of...
June 25, 2010
Is this code right? Declare Integer days, counter = 1 Declare Real penny = 1, salary, total = 0 Display "Enter a number of days." Input days Display "Days",TAB,"Salary While counter <= days Set salary = penny/100 Display counter, TAB, salary Set ...
May 21, 2010
What is the probability that a simple random sample of 56 special orders will provide an estimate of the population proportion of special orders specifying the color black that is within plus or minus .05 of the actual population proportion,assuming p = .36? In other words, ...
May 4, 2010
Replication of the E. coli chromosome takes 40 to 45 minutes, but the organism has a generation time of 26 minutes. How does the cell have time to make complete chromosomes for each daughter cell? For each granddaughter cell? my reponse was that the cells don't fully ...
March 29, 2010
This is one of the more helpful posts I found after finding this site on google, and it (like most others) is almost useless in its content related to the 1960's subculture.. and it is also filled with rude people telling its customers to search elsewhere.. I too will take...
March 11, 2010
actually if you state the documents out like that, you LOSE points and wont be able to go in the expanded core. just say "so and so stated this" and then in parentheses, say the document number. believe me ive been doing this without knowing, and my ap teacher just ...
March 6, 2010
URGENT help! 3. A rock sample was dated using potassium-40, Neasyrenebt ubducated tgat 1/8 of the original parent isotope is left in the rock sample. How old is the rock? 5. When a sample of lava solidfied, it contained 28g of uranium-238. It that lava sample was later found ...
March 5, 2010
Calculate the mass ( kg ) of the solute C4H8O and the volume ( mL ) of the solvent C6H6 that should be combined to generate 6450 g of a solution that is 2.07 m C4H8O. Density (kg/l) C4H8O 0.8892 C6H6 0.8786
February 1, 2010
So I have that 1.51 V - 1.065 V = .445 V = E and that ΔG = - 10 mol * 96485 J / mol*V * .445 V ΔG = -429358 J so then plugging in: K = e^(-(-429358)/(8.314 J/mol*K * 298 K)) K = 1.82 * 10^75 The 'correct' answer appears to be 1.5 * 10^75 , but that's not...
December 2, 2009
a store owner buys supplies from a vendor for $8,450. the terms of sale are 2/10, n/30. what will the net amount due be if the owner pays the bill by the 10th day after he receives the supplies?
November 23, 2009
Very close. Remember to change mm to meters. Greatly effects answer. Va/Vb = sqrt[(Tension1/Tension2)*(Diameter2^2/Diameter1^2)] Va/Vb = sqrt[(420/840)*((5.9E-4)^2/(1.3E-3)^2)]
November 20, 2009
you add the numbers together and divide by the how many numbers there are. Ex: 1+2+3+4+5=15 since there are five numbers (1,2,3,4,5) you divide by 5 15/5=3 3 is the average hope this helped!
November 9, 2009
Factors which effect reaction rates. 1) Concentration 2) Temperature 3) Presence of a Catalyst 4) Surface area 5) Orientation You store food in a fridge to prevent spoilage. Which factor are you applying to slow the rate of reaction? Which one of the following burns easily and...
September 21, 2009