Thursday

January 19, 2017
Total # Posts: 830

**Maths**

If the volume of a cylindrical block is equal to 800cm^3 prove that the total surface area is equal to 2(pi)x^2 + (1600)/x, where x cm is the radius of the base. hence obtain the value x which makes the surface area a minimum.

*January 4, 2017*

**Math**

65*50=3250ft^2 so 1625/3250 0.5$/ft^2

*January 4, 2017*

**math**

Amy & Ashley bike along the same trail. Amy bikes the entire trail at 20mph & Ashley bikes at 15mph. Amy finishes 8 minutes before Ashley. How many miles long is the trail?

*December 13, 2016*

**Chemistry**

Suppose you titrated a sample of sulfuric acid (diprotic acid) with a 0.250 M solution of NaOH. Given the data in the table below, what is the concentration of the sulfuric acid solution?

*December 6, 2016*

**Math**

f(x) = cos(x) + 3x Find f^-1 (1) and (f^-1)' (1) f^-1 (1) = 0 (f^-1)' (1) = 1/3 These are the answers given, but I also don't understand how my teacher got these.

*December 5, 2016*

**Math**

Actually I do have one question, how do we know that x is 1 already ???

*December 5, 2016*

**Math**

Thank You so much!

*December 5, 2016*

**Math**

f(x) = x^5 + 2x^3 + x - 1 Find f^-1 (3) and (f^-1)' (3) f^-1 (3) = 1 (f^-1)' (3) = 1/12 Those are the answers, but I have no clue how my teacher got them.

*December 5, 2016*

**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**

I cant find the exact answer from above 3 answers.

*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*

**Science**

Free fall

*May 10, 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*

**Check my Essay Plz?!**

9/10

*January 25, 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*