Saturday
December 3, 2016

# Posts by dave

Total # Posts: 818

Math
lim 200 (30-t)^2 h->0 t=10 The answer should be -8000, but I keep getting -80,000 because I have to do it the long way.
December 1, 2016

math
a truck weighting 20000 pounds going 5 mph what is the force of the truck when it hits a person and comes to a complete stop?
November 5, 2016

Math
There is a graph of a function that looks like y = x^4 , but it has a vertical asymptote at x = -2 and x = 4. The question then asks us to arrange the following numbers in decreasing order: g'(1), g'(-2), g'(0), g'(2), g'(4) I figured out all of the slopes...
November 3, 2016

Math
Is the step function differentiable in its domain? I answered it and said that the step function is not differentiable in its domain because it is not continuous. For the a function to be differentiable it would need to have a value and a limit. However, the step function has ...
November 3, 2016

Mats Exercise 1.7
g (x)= 2\3 (2/3x) (x-2) (x+1)
October 25, 2016

Math
Find the 999th derivative of cos x. I got sin x.
October 20, 2016

Math
lim (cos(π/4 + h) - cos (π/4)) / h h->0
October 20, 2016

Math
lim (cos(π/4 + h) - cos (π/4)) h->0 _________________________ h Somehow I ended up with cos(1).
October 20, 2016

Math
Use the quotient rule to find the derivative of cot x. I tried to solve this, but somehow I got (sec^2x)/(tanx)^2.
October 20, 2016

physics
Identify the force that propels a rocket. 1)The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. 2)The rocket is propelled because the action force of the rocket on the exhaust gases is greater than the reaction...
October 18, 2016

physics
Identify the force that propels a rocket. 1)The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. 2)The rocket is propelled because the action force of the rocket on the exhaust gases is greater than the ...
October 18, 2016

math
find the lcm for 6, 18
October 16, 2016

History
What kind of scenes did artists who gained fame tend to paint in the late eighteenth century. Give an example.
October 13, 2016

US History
What kind of scenes did artists who gained fame tend to paint in the late eighteenth century. Give an example.
October 13, 2016

Math for Reiny
your derivative is correct. now just plug in x = π/2 to get the slope remember that tan(π/2) is undefined, BUT cot (π/2) = cos(π/2) / sin(π/2) = 0/1 = 0 so slope = -csc^2 (π/2) = 2 I calculated and got -1 as the slope. Can you please explain how ...
October 12, 2016

Math
Find the inverse of: y = ((-1) / (x+5)) - 1
October 12, 2016

Math for Reiny
your derivative is correct. now just plug in x = π/2 to get the slope remember that tan(π/2) is undefined, BUT cot (π/2) = cos(π/2) / sin(π/2) = 0/1 = 0 so slope = -csc^2 (π/2) = 2 I calculated and got -1 as the slope. Can you please explain how ...
October 12, 2016

Math
I calculated and got -1 as the slope. Can you please explain how you got 2 for the slope?
October 11, 2016

Math
Find an equation for the tangent line to the curve at (π/2 , 2). y = 4 + cot(x) - 2csc(x) I am confused how to take the derivative of this problem. When I tried to solve it I ended up with -csc^2 (x) + (2csc(x) * cot(x)). From there I can't seem to simplify it. Also, ...
October 11, 2016

Physics
Why does the force of gravity change the speed of a satellite in an elliptical orbit? 1)The force of gravity is always tangent to the satellite motion. 2)Gravity speeds up the satellite as it moves away and slows it on its return. 3)The force of gravity is always perpendicular...
October 7, 2016

Physics
Why does the force of gravity change the speed of a satellite in an elliptical orbit? 1) The force of gravity is always tangent to the satellite motion. 2)Gravity speeds up the satellite as it moves away and slows it on its return. 3)The force of gravity is always ...
October 7, 2016

Physics
How can gravity be simulated in an orbiting space station? 1)aped like a bicycle wheel 2)Spin two pods connected by a cable 3)Rotate a cylinder to create centrifugal force as viewed by a person on the inside of the curved outer wall 4)All of the above
October 7, 2016

Physics
Which of the following is an element? H2O Hydrogen Carbon dioxide A supernova
October 7, 2016

Physics
Which two factors mainly affect ocean tides on Earth? Check two answers. Earth's revolution about both the Moon and the Sun the Moon the Sun the pull of distant planets
October 7, 2016

physics
October 7, 2016

physics
The concept of pressure involves both force and volume. force and area. area and volume
October 7, 2016

Physics
Why does the force of gravity change the speed of a satellite in an elliptical orbit? 1)The force of gravity is always tangent to the satellite motion. 2)Gravity speeds up the satellite as it moves away and slows it on its return. 3)The force of gravity is always perpendicular...
October 7, 2016

Physics
A dike in Holland springs a leak through a hole of area 0.80 cm2 at a depth of 1.2 m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak?
October 6, 2016

Physics
A dike in Holland springs a leak through a hole of area 0.80 cm2 at a depth of 1.2 m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak?
October 5, 2016

Physics
A dike in Holland springs a leak through a hole of area 0.80 cm2 at a depth of 1.2 m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak?
October 5, 2016

Math
Find 2 tangent line equations to the curve y=x^3+x at the points where the slope of the curve is 4. What is the smallest possible slope of the curve? At what x-value(s)does the curve have this slope? So far I have figured out the derivative of this function is y'= 3x^2+1. ...
October 5, 2016

Math Pre- Algebra
2 (75+7.50) or (75+7.50) (2) The total should be 165 dollars.
October 5, 2016

Math
lim as x approaches negative infinity (3x^5 + 6x + - 3) / (8x^4 + 10) a. Does Not Exist b. 0 c. -3/8 d. 3/8 I solved this and got negative infinity as the answer, but none of the answers are listed above. I finally chose Choice C, but my teacher said the correct answer is A?
September 26, 2016

Math
lim as x approaches negative infinity (3x^5 + 6x + - 3) / (8x^4 + 10) a. Does Not Exist b. 0 c. -3/8 d. 3/8 I solved this and got negative infinity as the answer, but none of the answers are listed above. I finally chose Choice C, but my teacher said the correct answer is A?
September 26, 2016

Calculus
Construct a function f : R 2 ¡æ R such that its saddle points are given by {(n, 2m+1−n)|n ¡ô Z, m ¡ô Z}, where Z is the set of integers.
September 26, 2016

Math
The limit as x approaches negative infinity is (3x^5 + x + 2) / (8x^4 - 5) a. DNE b. 0 c. -3/8 d. 3/8 I think the answer is Choice C, but I was stuck between this answer and Choice D.
September 23, 2016

History
They systematic raiding of the Athapascans shows that organized warfare is most clearly identified with: a. there is no record of either society initiating organized warfare b. both farming and hunting societies c. neither hunting nor farming societies d. farming societies ...
September 14, 2016

History
The map of northeastern region of North America shows the tribes of the Iroquois Confederacy: a. in a staked formation south of the st. lawrence river b. arranged like fingers south of lake ontario c. formed in the shape of a necklace north of the ohio river
September 14, 2016

History
I chose choice A.
September 14, 2016

History
Teotihuacan like other early urban civilizations was a. self sustaining and unconcerned with long distance trade as a result of its abundant food supply and specialization of labor b. controlled as an elaborate state sponsored trading system that stretched from present day ...
September 14, 2016

History
They systematic raiding of the Athapascans shows that organized warfare is most clearly identified with: a. there is no record of either society initiating organized warfare b. both farming and hunting societies c. neither hunting nor farming societies d. farming societies ...
September 14, 2016

Math
380/95 is exactly 4 hours.
August 31, 2016

Maths
I have a wheel 40 cm diameter that has 200 N m of torque, assuming there is no slippage what would the force of the wheel on the road? How do I work it out please?
August 16, 2016

Civics
To become a law, typically a bill must be approved by: a. The House of Representatives, the Senate, and the President b. The House of Representatives c. The Senate d. The Supreme Court I chose Letter A, but someone how my teacher said it was incorrect. I was completely shocked...
July 19, 2016

Civics
To become a law, typically a bill must be approved by: a. The House of Representatives, the Senate, and the President b. The House of Representatives c. The Senate d. The Supreme Court I chose Letter A, but someone how my teacher said it was incorrect. I was completely shocked...
July 18, 2016

Civics
I think C is the correct answer.
July 18, 2016

Civics
What limits the amount of legal immigrants to our country? a. Tariffs b. Census c. Quotas d. Passports I couldn't find this question on any sources online. My teacher originally gave us this question on the review packet with no answer right answer to it. So, I just ...
July 18, 2016

Civics
Thank you so much for your help Writeacher!!!
July 18, 2016

Civics
I think it was 5 years at least. Thank you so much for your help Ms. Sue!!!
July 18, 2016

Civics
Hi Ms. Sue! I couldn't find anything on the declaration of intention on the website provided. I thought that Letter B wouldn't part of the process, but you need to have a basic understanding of the gov't and english to pass the test. And to do this you need to take...
July 18, 2016

Civics
I chose Letter A, but my teacher said it was incorrect. I don't know what is the correct answer for this one.
July 18, 2016

Civics
Which of the following is NOT part of the naturalization process? a. Filing a Declaration of Intention b. Taking a US history, gov't, or English language class c. Living in the US for 10 years d. Taking an Oath
July 18, 2016

Civics
health, safety, and moral standards of the community
July 18, 2016

Civics
I chose Letter D, but my teacher also said that it was incorrect.
July 18, 2016

Civics
Our rights are sometimes restricted in order to protect: a. those that are offended easily b. health, safety, and moral standards of the community c. the government from being overthrown d. individual rights
July 18, 2016

History
To become a law, typically a bill must be approved by: a. The House of Representatives, the Senate, and the President b. The House of Representatives c. The Senate d. The Supreme Court I chose Letter A, but someone how my teacher said it was incorrect. I was completely shocked...
July 18, 2016

physics
The contestants at a cycling race travel around a 0.5km radius track. The peloton travels 33 laps in 1 hour to complete the race. What is the total angular distance they have traveled? On the first lap, they start from rest and after traveling ½ the circumference of the...
June 30, 2016

physics
The general form of a number in scientific notation is a x 10n, where a must be between 1 and 10, and n must be an integer thus 100 is 1x10^2 indicating 2 zeros or decimal moved 2 places now .001 is 1x10^-3 as it moved the opposite way. there are 2.2 cm in an inch so there are...
June 27, 2016

Algebra
Wrong. It can't be 32miles per hour as x 4 hrs that is the full 128 miles. What happened to the slower cyclist? Distance = speed x time Let s stand for cylcist 1 speed. Therefore cyclist 2 speed must be 3s. The equation then looks like this 128 = 4s x 4 128 = 16s 8 = s so ...
June 15, 2016

Math
A pharmaceutical salesperson receives a monthly salary of \$2500 plus a commission of 7 percent of sales. Write a linear equation for the salesperson monthly wage in terms of monthly sales.
June 7, 2016

Physics
The worker pushes with a force of 10 N that points downward at an angle of 45° below the horizontal. What component of the force moves the crate forward? I do not know how to set up this problem, so any help would be appreciated.
May 31, 2016

Math
a geometric progression has a third term of 20 and a sum to infinity which is three times the first term. find the first term
May 12, 2016

Math
a sum to infinity which is three times the first term. find the first term
May 12, 2016

Calculus
Use Simpson's rule with n = 4 to approximate. Keep at least 2 decimal places accuracy. Integrate: (cos(x))/(x) x=1 to 5
May 3, 2016

chem
Determine the mass of oxygen in a 7.2-g sample of Al2(SO4)3
April 18, 2016

chemistry
A sample of water is known to contain 1.51 × 10^24 H2O molecules. How many moles of H2O molecules are present in the sample?
March 22, 2016

Math Algebra Intermediate
How do I Factor the expression a y - a^{6} y^{6} ?
March 4, 2016

Chem
What type of orbitals are used to form the N–N bond in hydrazine, N2H4?
March 2, 2016

Chemistry
What set of hybrid orbitals is used by Xe in XeO3F2? dsp2 d2sp3 sp3 dsp3 d2sp
March 2, 2016

Marshall Middle
Of 450 lunches old at school on Thursday, 40% were hamburgers and the rest were pizza. How many  more pizza lunches were sold than hamburgers?
February 28, 2016

Trig
a 12-ft-long guy wire is attached to a telephone pole 10.5 ft from the too of the pole. If the water forms a 52 degree angle with the ground, how high is the telephone pole?
February 17, 2016

maths
a sheet of 8 x 4 ply how many sheets to cover 13ft 6 x 13 ft
February 16, 2016

Math
Can somebody show or explain this to me: Change 6 2/3% to fraction and .6 1/3 to a decimal or fraction.
February 13, 2016

Finance
Celeste just borrowed 47,500 dollars. She plans to repay this loan by making equal quarterly payments of 3,126.28 dollars for 19 quarters. If she makes her first quarterly payment later today, then what is the quarterly interest rate on the loan?
February 1, 2016

Maths
depends on the sequence
January 25, 2016

Math
Lim sin(60-x)/2cosx-1 x approaches 60
January 2, 2016

math
on office equipment sales representative earns a weekly salary and commission on his sales. one week his total compensation on sales of \$7000 was \$700, the next week his total compensation on sales of \$8000 was \$740, find the weekly salary and commission rate
December 13, 2015

Math
What is the percentage chance that the same number can be pulled twice when there are 12 numbers in a hopper? If the number that is pulled is placed back in the hopper and then pulled for a second time what is the chance that the same number is pulled for the second time?
December 9, 2015

Physics
A brick is initially 12.90 cm high and an aluminum can is initially 12.91 cm high. By how much must their temperatures be raised in order for the brick and the can to have exactly the same height?
December 8, 2015

Physics
A 1.05 liter flask contains a certain quantity of ideal gas at 305 K. Then an equal number of molecules of the same gas is added to the flask, after which the absolute pressure is 1.55 times its original value. What is the final temperature?
December 8, 2015

Physics
By how much does the air pressure in a house increase if the house is sealed and the air temperature increases from 10.7° C to 21.0° C? The initial air pressure is 1.00 atmosphere.
December 8, 2015

Physics
Find the volume occupied by 3.14 moles of an ideal gas at standard conditions of pressure and temperature (P = 1.00 atm, T = 273 K).
December 8, 2015

Physics
A watertight car is submerged under water. What force is required to open a door of area 1.12 m2 if the average depth of water at the door is 1.50 m?
December 8, 2015

Physics
A certain concrete will support a maximum compressive stress of 1.30 107 N/m2 before being crushed. A column of uniform width is to be made with this concrete. How tall can the column be if the stress in it at any point is not to exceed one half the maximum value? The weight ...
December 8, 2015

Physics
A man doing a slow push-up is approximately in static equilibrium. His body is horizontal, with his weight of 750 N supported by his hands and feet, which are 1.36 m apart. One hand rests on a spring scale, which reads 268 N. If each hand bears an equal weight, how far from ...
December 8, 2015

Calculus
Gloria would like to construct a box with volume of exactly 45ft^3 using only metal and wood. The metal costs \$15/ft^2 and the wood costs \$6/ft^2. If the wood is to go on the sides, the metal is to go on the top and bottom, and if the length of the base is to be 3 times the ...
November 4, 2015

math
5 inches is what fraction of a foot? A. 1/3 B. 1/2 C. 5/12 D.5/24 my answer is C. is it correct?
October 27, 2015

Math
I think the domain would be (-∞, 7]. I am not sure if it is correct. I got the above part correct though.
October 13, 2015

Math
The above function is given: f(x)= sqrt of (2x-6)/(x-8) - Sarah describes the domain as [3, ∞). - Describe why her domain is incorrect. - Provide the correct domain for the function. (I sort of understand this).
October 13, 2015

Maths
I need some help with my maths questions please! What angle does the tangent to the curve y=x^4-x^3+7x make with the positive direction of the x-axis at the point where x=2? Find any x values for which the gradient of the tangent to the curve y=x^2-3x-1 is parallel to the line...
October 13, 2015

math
Consider the equation f(x)= -2 sqrt(X+3). List in order the transformations applied to the parent function.
October 9, 2015

math
How can you get the answer x = -215.91, 167.45
August 30, 2015

math
August 30, 2015

chemistry
if 1.37 moles of Pb(NO3)2 is mixed with 2.56 moles of KI, how many moles of PbI2 are produced?
August 30, 2015

trig/calc
sorry steve you failed All angles of a triangle add up to 180 degrees, so you have 2 angles you can Find the third angle by 180-58-67=55 Now use the law of sines...(capital is the angle and lower case the side across from said angle you have the 3 angles now and 1 side use law...
August 16, 2015

Math
Find the area of a triangle with base of 15 m and altitude of 12 m
August 6, 2015

Physics, Eectric flux
A cubical Gaussian surface surrounds three positive charges, each has a charge q1 = +4.00 × 10-12 C, and two negative charges, each has a charge q2 = −2.30 × 10-12 C as the drawing shows. What is the electric flux passing through the surface?(The permittivity...
July 13, 2015

Math
Find r in a geometric sequence if A=2 and A10=1024
June 23, 2015

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