Posts by ray

Total # Posts: 636

Chemistry (molarity)
What would the effect on your molarity of NaOH be if you had added 35 mL of water to dissolve the KHP (acid) instead of 25 mL? Explain. My answer so far is that adding more water shouldn't affect the molarity at all because water does not account for the reaction between ...

Algebra
I'm trying to rewrite 3x^2*e^-x*tan(4-x) Can I rewrite it as 3x^2*tan(4-x)/e^x ?

Algebra
Just a quick algebra question, if I had (e^x)/(x^3+x^-3) could I rewrite it as : (e^x)+(x^3)/(x^3) ?? (flipped the negative exponent from the bottom and made it positive on top)

Chemistry (Concentratrion/molarity)
A 25.00 mL aliquot of HCl of unknown concentration is titrated with 25.62 mL of 0.1011 M NaOH. What is the molarity of the HCl solution?

Chemistry help emergency? (theoretical mass/mol)
I am supposed to calculate the theoretical mass and moles of Cu. However I am given the mass of 2 reactants in the balanced equation: 3CuCl2*2H2O + 2Al -> 3Cu + 2AlCl3 + 6H2O I am given the mass of CuCl2*2H2O to be 0.477g and the mass of Al is 0.267g. If I wanted to ...

Calculus differentiable and continous identify
1. Which of the above functions are not continuous where they are defined? Why? 2. Which of the above functions are not differentiable where they are defined? Why? Photo Link: goo.gl/photos/2RPU1dAWoKzUn4Pf8 For the first question, I said that graph F is not continuous because...

Math (Continuous/Differentiable)
Any ideas?

Math (Continuous/Differentiable)
goo.gl/photos/2RPU1dAWoKzUn4Pf8 1. Which of the above functions are not continuous where they are defined? Why? 2. Which of the above functions are not differentiable where they are defined? Why? For the first question, I said that graph F is not continuous because of a jump, ...

Math Derivative
Find derivative of f(x)=g(h(x)) Would the derivative be something like: g'(h(x))*h'(x) ??

Math (Finding Vertical Tangent)
Or near x=2, that was pretty easy, can't believe I didn't spot it at first

Math (Finding Vertical Tangent)
At first I said x=-3 but that is a vertical asymptote, not a vertical tangent. Where does this graph have vertical tangents in this case?

Math (Finding Vertical Tangent)
List all x values where the graph of f(x) has vertical tangents goo.gl/photos/iPu1SHA8yyBFTcZj6

Math (Derivative)
Compute derivative using the definition of the derivative. f(x)=1+1/x^2 1+ 1/(x+h)^2 - (1+ 1/(x^2)) ------ divide by h and multiply by reciprocal 1/h(x+h)^2 - 1/hx^2 Next I expanded it and got this messy huge number and multiply the bottom of each other after cancelling some ...

Math (Derivative)
.. the minus made the x from the right side which forces those two to cancel out. I'm totally overlooking this problem than it needs to be. Thanks for helping me clarify a rather simple problem!

Math (Derivative)
Yes I know the definition of the derivative, I think I'm just confused on the algebra part. x+h - 1/(x+h) Just that left side of the equation is where I'm lost. It went from that to h-1/(x+h) Did that x just got canceled out from the left hand side? Other than that, I ...

Math (Derivative)
How did that h on the left right below "subtract" come from??

Math (Derivative)
Computer the derivative of f(x)=x-(1/x) for x>0 using the definition of the derivative.

Math (Limits)
So I can just say for example, plug values as y gets closer to 1 and solve for the function and notice that the function is getting smaller and smaller (negative) and therefore negative infinity?

Math (Limits)
lim ln(y-1) y->1+ The answer is negative infinity but how do I show the logic of proving that it's negative infinity? I plugged in "1" to the function and got ln(0) which is obviously impossible? Thanks in advance

Chemistry
Methane, CH4 is the main component of natural gas which is used for cooking in many homes. The molar heat of combustion of methane is -890kj/mol. A cook wants to boil some water on a gas stove. If the stove burns 5.00g of methane to heat 2575 ml of water, what is the ...

Chemistry
Silicon carbide (SiC) is made by reacting sand (Silicon dioxide, SiO2) with powdered carbon at high temperature. Carbon monoxide is also formed. What is the percent yield if 51.4kg of SiC is recovered from processing 100.0kg of sand? What mass (in kg) of carbon would be needed...

Math
6 softball teams are to play each other once. how many games are needed?

Science (Chemistry) (Yield)
I tried doing some conversion factors and came up with this: (0.101g Mg)(1mol MgO) |(40.31g MgO) ---------------------- (24.31g Mg)|(1mol MgO) =~0.167g MgO as my theoretical yield if I had a mass of 0.101g of Mg Did I do this correctly?

Science (Chemistry) (Yield)
Using your mass of Mg (0.101g), and assuming all of the Mg burns in oxygen and forms the theoretical predicted product, calculate the theoretical yield of magnesium oxide. I wrote out the equation and it turned out to be: 2Mg+O2->2MgO I have my mass of Mg but how do I get ...

Physics
A ball is on the end of a rope that is 1.75 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 78.0° with respect to the vertical. What is the tangential...

Chemistry (atoms)
How many atoms of oxygen, O, are in 0.0595 moles of water?

math (horizontal tangent line)
Determine the point(s) if any at which the graph of the function has a horizontal tangent line. y=x^3+x I graphed this function out and it looks like there isn't any horizontal tangents. Am I correct or am I forgeting something? I tried finding the derivitave of the ...

Math (Calculus)
Determine if each of the following functions is in Big-O, is Big-Omega and is Big-Theta of x: (Could be multiple) a) f(x)=10 b) f(x)=3x+7 C) f(x)=x^2+x+1 d) f(x)=5log(x) e) f(x)=|x| f) f(x)=x/2 I'm in calc 1 and I have no idea what's it even asking me. Help? Thanks in ...

Health care tech
I would say it's all of those. All of your equipment would be useless if there wasn't any software telling them what to do!

Math (Calculus)
Determine if each of the following functions is in Big-O, is Big-Omega and is Big-Theta of x: (Could be multiple) a) f(x)=10 b) f(x)=3x+7 C) f(x)=x^2+x+1 d) f(x)=5log(x) e) f(x)=|x| f) f(x)=x/2 I'm in calc 1 and I have no idea what's it even asking me. Help? Thanks in ...

Technology and online learning
Remember we're looking at its validity of a website. Therefore you wouldn't want biased information. Yeah sure the website may be professional looking, but that doesn't mean that it's valid and genuine. You would want up to date and accurate information instead...

Math (Function differentiable)
Any ideas?

Math (Function differentiable)
Determine whether the function is differentiable at x=2 x^2+1 for x<(or equal to) 2 4x-3 for x>2 I did the math for the limits of both equations and they both approach to 4. So that means they are differentiable right?

Math
The density of water at 21 degrees C is 0.997992 g/mL. The density of water at 22 degrees C is 0.997770 g/mL. What is the density of water if the room temperature is 21.3 degrees C?? So I would just multiply 30 percent of the density at 21 degrees C but I'm stuck on how to...

Science (Chemistry) Ratio of mole
I understand your math, but where did Oxygen started with 2 of them to be O2? Is it because of the charges?

Science (Chemistry) Ratio of mole
You measured out 0.101g of Mg. You heat the sample and measure out 0.234 of the magnesium oxide compound. Given your data, what us the empirical formula for the Mg(x)O(y)? x and y are ratio x:y If I'm doing this correctly, I divided 0.101g of Mg/24.31g of Mg = .00415 mol ...

Math (derivative by limit process)
Find the derivative of the function by the limit process. f(x)=1/sqrt(x) I've worked through my problem and got f'(x) to be -1/2x but the actual answer is -1/2x^3/2? Where did the 3/2 power come from? Any help is greatly appreciated!

AMDM1
The amount of paint a painter needs is directly proportional to the area of the object he is painting. If a painter needs g gallons of paint for every s square feet that he paints, what is the total amount of paint that he needs to paint a house in terms of g and s?

Math (Instanttaneous rate of change)
I see, this was a lot simpler than I expected! Thanks so much

Math (Instanttaneous rate of change)
Compute the instantaneous rate of change f'(a) for the function f(x) at x=a using: f'(a)=lim(h->0) (f(a+h)-f(a))/h f(x)=x^2 at x=3 My teacher didn't even go over the problem since class was over but gave us the answer being 6. How do you approach this problem to...

Math/Chemistry
Aren't we supposed to multiply 50.0g by 0.001? Where did 1E^-5 come from?

Math/Chemistry
Your friend eats 50.0g tuna steak. You find out that the tuna is 0.001% (by mass) mercury. The lethal dose of mercury is 5.5x10^-3 mg of mercury. Should you take your friend to the hospital?

Math (Limits)
Consider the following function. f(x) = 2x^2 − 8x Find the limit. lim (Δx->0) (f(x+Δx)-f(x))/(Δx) How would I set up the equation to work with that function? I know how to plug in the values usually, but how would I do this for that function ...

Math
$20.00-$9.50=$10.50 The customer will receive $10.50 in change for paying a movie ticket at $9.50 with a $20.00 bill.

Math (Continuity)
Got it, thanks for the help!

Math (Continuity)
Find the x-values (if any) at which f is not continuous. Which of the discontinuties are removable? f(x)=(x)/(x^2-4) I'm not sure how to do this problem but I know that it is not continnous at x=2?

Math (Expanding logarithms)
Use the properties of logarithms to expand this functiion? ln[ (x^2+1) (x-1) ] So assuming this is a multiplication problem, I would be using the product rule for expanding logs. I tried applying the product rule but I'm not sure if this is correct or not? ln(x^2+1)+ln(x-1)

Science (Chemistry) (Measurement Uncertainty)
Anyone?

Science (Chemistry) (Measurement Uncertainty)
It's the mass of a coin, not coon*

Science (Chemistry) (Measurement Uncertainty)
Three students are asked to determine the mass of a coon. They each measure different values for the mass of the coin using a balance. Student A recorded a mass of 63.08g, student B recorded a mass of 63.022g and student C recorded a mass of 63.0328g. If the balance is ...

Math (Limits)
Alright thanks, just wanted to double check because for some reason my teacher only allows us one attempt on each question on our online homework. Life is so unfair.

Math (Limits)
I'm not sure either. But I think it is more of a hypothetical question because another question asked me: "What is the limit of f(x)=7 as x approaches pi?" and that answer was 7.

Math (Limits)
What is the limit of g(x)=x as x approaches pi? Would it just be pi??

Math (Domain and range)
Evaluate the function f(x)={9x+5, x<0 {9x+6, x>(or equal to)0 Determine its domain and range using interval notation? I believe the domain is (-infinity,infinity) but how would I find the range?

Math (Perpendicular equation)
Write the equation for the line through the given point and perpendicular to the given line. Point: (4/5,9/10) Line: 6x-4y=0 I tried doing this problem and got 0=-4/6x-y+43/30 as the perpendicular equation. Is this correct?

Math (Secant Lines)
Any ideas?

Math (Secant Lines)
So far I tried to figure out the slope of each secant line: For x=1 the slope is 1/3 For x=3 the slope is 2-sqrt(3) For x=5 the slope is sqrt(5)-2

Math (Secant Lines)
Consider the function f(x)=sqrt(x) and the point P(4,2) on the graph of f? -Consider the graph f with secant lines passing through p(4,2) and Q(x,f(x)) for x-values 1, 3, and 5. -Find the slope of each secant line -Use the results to estimate the slope of the tangent line to ...

Math (Condensing logarithmic expression)
Write the expression as the logarithm of a single quantity 3[(ln x) -2ln(x^2+1)]+2 ln 5?

Math (Expanding logarithmic expression)
Use the properties of logarithms to expand the logarithmic function ln[(x^2+1)(x-1)] Would this be the correct answer? ln[x^3-x^2+x-1] I can't seem to expand it any further than that.

Math (Finding points of intersection)
Thanks for the correction! I understand now

Math (Finding points of intersection)
Find the points of intersections of these equations? x^2+y^2=1 -x+y+1 This is what I've done so far, I isolated the y's out y= +/- sqrt(1-x^2) y=x+1 But I am stuck on how to make them together in order to find the point of intersection, any help is greatly appreciated!

Math (Trig Review)
Evaluate the expression without using a calculator (Make a sketch of a right triangle) tan(arccot 2) Thanks in advance! I'm trying to refresh my memory of these kinds of problems and I'm having trouble on how to solve this problem

Math
In how many different ways can six of ten people be seated in a row of six chairs? I don't have the answer, but from my rough understanding of permutations and combinations, I got: 10C6 * 6! = 210 * 6! I figure first 6 people have to be chosen out of the 10, and that can ...

math
1/4 mile long and 1/4 mile wide. so he had 16 fields in the beginningng

math
suppose the farmer buys another 1/2 square mile of land and divides all his land into square fields 1/4 mile long and 1/4 mile wide. how many fields will he have?

algebra
Ms. Kork sold her car for $8700. This was $100 more than 2/5 of what she paid for the car originally. How much had ms. Kork paid for the car??

algebra
The pressure on a scuba diver at sea level is 14.7 pound psi.The pressure increases 0.0445 psi for each foot of depth. Suppose the diver is 32.5 psi. How deep is he?

English
Did Lucy really say I refuse to ride with Tom? Should there be quotation marks before I and after the question mark?

algebra
the probability of winning a particular game at the game store is one fourth. fine the odds of winning the game

History
What are unintended outcomes of Federal Indian Boarding Schools?

Math (Polar to Cartesian Equation)
Convert the given polar equation to a Cartesian equation. r^2=4sec(theta)csc(theta)

Help please?
Any ideas anyone?

Math (Parametrics)
I know setting x(t)=cos(t) and y(t)=-sin(t) will make the circle travel clockwise but I'm not sure exactly on how I can make it start at the specific point (0,1)?

Math (Parametrics)
Find the parametric equations of a unit circle where you start at point (0,1) at t=0 and you travel clockwise with a period of 2π? x(t)=? y(t)=?

Math (Vectors)
In this case, would a=-15 and b=3?

Math (Vectors)
Determine the values of a and b in the following vectors for the indicated property. m=<10,a,15> and n=<2,-3,b> and vector m is parallel to vector n. Thanks in advance!

Math (Vectors)
Thanks for the help! I wanted to ask how did you know that we're supposed to divide (7.2/5.7) and not the other way around?

Math (Vectors)
Consider the vector v=-5.7i-7.2j Approximate to the nearest tenth of degree the angle vector v makes with the positive horizontal direction?

Math
A father who is 42 years old has a son and a daughter. The daughter is three times as old as the son. In 10 years the sum of all their ages will be 100 years. How old are the two siblings at present? Please help quick!

Chemistry
How many grams of solute are present in 795 ml of 0.130m KBr?

LIFE ORIENTATION
The question below is based on the recent corruption activities by our former president Jacob Zuma related to Nkandla. Evaluate the physical, social and economic consequences of this crime to the offender. How did this corruption and fraud impact negatively in the country: for...

(Arts/Theater)(Stuck on what to do) Help please?
Thanks for your possible ideas! Maybe drawing might work since that's pretty simple. I'm terrible at drawing but I think I could come up with something with that. Suppose copying a simple drawing would take about 10 minutes.

(Arts/Theater)(Stuck on what to do) Help please?
I suppose tying a tie might work. Would that really take 10 minutes to complete that action though? haha

(Arts/Theater)(Stuck on what to do) Help please?
My improvisation teacher today told us to bring something with us to class where you can do a physical action with it. This action must be something you can do in barely 10 minutes and must have an actual ending to that action. We're doing this assignment tomorrow and I ...

Writing Sentences and Paragraphs
Another edit... Paragraph 1 I am applying for the position of Data Entry in the Archives Department at DC Comics because of the enthusiasm I have for my hobby of collecting and cataloguing comic books. While I was studying as a Library Technician at Fanshawe College, I ...

Writing Sentences and Paragraphs
This is my 2nd revision of Paragraph 1 ...any feedback and suggestions would be appreciated. Paragraph 1 The enthusiasm I have for my hobby of collecting and cataloguing comic books is why I am applying for the position of Data Entry at DC Comics. While I was studying as a ...

Writing Sentences and Paragraphs
I deleted a couple of things...these are the individual sentences I have so far... The enthusiasm I have for my hobby of collecting and cataloguing comic books is why I am applying for the position of Data Entry at DC Comics. While I was studying as a Library Technician at ...

Writing Sentences and Paragraphs
As an individual with experience performing office clerical duties and educated as a Library Technician, I am excited to apply for the position of Data Entry Clerk as advertised on the DC Comics website. I consider that my experience and skills match ver well with your ...

Math 142 (Pre-Cal) (Circles)
A wheel has a radius of 10 inches is rotating with an angular velocity of 2.5 revolutions per second. Find the distance the wheel travels in 15 seconds.

Math 142 (Pre-Cal) (Circles)
Is my answer correct? w=(29/1)(2pi/1) w=~182.2124 rad/min v=(1.8)(182.2124) v=~327.9823 feet/min

Math 142 (Pre-Cal) (Circles)
A wheel spins through 29 revolutions per minute. Find the angular velocity and the linear velocity if the radius of the wheel is 1.8 feet. w=? (rad/min) v=? (feet/min)

math
no all of u are wrong i typed in my answer and all the answers u gave me were wrong

statistics
Find the following: P(z > 2.43)

Statistic
What percentage of the area of the standard normal distribution is between z = -2.00 and z = +2.00? How do you know this?

Statistics
In testing a new drug, researchers found that 20% of all patients using it will have a mild side effect. A random sample of 25 patients using the drug is selected. Find the mean and standard deviation of patients having a mild side effect. Mean = np = 25(.2) = 5 Ok Standard ...

Math (Pre-Cal)
The number of Sasquatch living in northern Ecotopia t years after 2016 is given by the formula s(t)=3(1.12)^t . Determine how long it will take for the Sasquatch population to double. Do this algebraically?

physics-please answer
A coconut thrown horizontally at 20 m/s from the top of a hill 63 m high. How far from the base of the hill does the coconut hit the ground? Select one: a. 42 m b. 13 m c. 66 m d. 72 m

Math (Pre-Cal) (Exponential Functions)
A car was valued at $38,000 in the year 2003. The value depreciated to $11,000 by the year 2009. Assume that the car value continues to drop by the same percentage. -What will the value be in the year 2013?

math (pre calc)
Imagine that you are driving 150 miles and you want your average speed for the trip to be 60 miles per hour.Imagine that you drive the first half (by distance) of the trip at 50 mph. How fast must you drive on the second half to make your average speed for the whole trip 60 ...

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