# Posts by help

Total # Posts: 1,481

**math**

how do yu find the implicit differentiation for this porblem 4cosx*siny=1

**math**

Find two point on a circle x^2+y^2=1 where the slope of the tangent line is -2 write the equation for the normal lines at these points.

**math**

For the given function, find all points on an the graph where the tangent line is horizontal or vertical. y= xsqrt(4-x^2) y= sqrt(1-x^2)(4-x^2)

**chemistry**

225g

**chemistry**

43g

**chemistry**

of KCl

**chemistry**

A solution was prepared by dissolving 43.0 of in 225 of water. Calculate the mass percent of in the solution.

**math**

how?

**math**

wat is the answer for the pattern 1,3,6?

**physics**

The flywheel of a steam engine runs with a constant angular speed of 164 rev/min. When steam is shut off, the friction of the bearings and the air brings the wheel to rest in 1.6 h. I found the constant angular acceleration as 1.71rev/min^2. They also ask you to find What is ...

**Biochemistry**

What is the net ionic equation for Phosphate ion + ammonium molybdate in the presence of nitric acid?

**physics**

A coin with a diameter of 1.9 cm is dropped on edge onto a horizontal surface. The coin starts out with an initial angular speed of 19 rad/s and rolls in a straight line without slipping. The rotation slows with an angular acceleration of magnitude 2.1 rad/s2. What is the ...

**physics**

The flywheel of a steam engine runs with a constant angular speed of 164 rev/min. When steam is shut off, the friction of the bearings and the air brings the wheel to rest in 1.6 h. I figured out the constant angular acceleration=1.71 rev/min2 but im not sure how to find:What ...

**phsics**

A coin with a diameter of 1.9 cm is dropped on edge onto a horizontal surface. The coin starts out with an initial angular speed of 19 rad/s and rolls in a straight line without slipping. The rotation slows with an angular acceleration of magnitude 2.1 rad/s2. What is the ...

**phsics**

thanks that makes sense

**phsics**

You plan to throw stones by using a sling of length 1.8 m which you whirl over your head. Suppose you wish to throw a stone a distance of 29 m. What must be the centripetal acceleration of the stone just before its release if it is to reach this distance? Assume that the ...

**physics**

An arrow, starting from rest, leaves the bow with a speed of 16.5 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the arrow leave the bow?

**physics**

A bat flying in a cave emits a sound and receives its echo 0.3 s later. How far away is the cave wall? Assume the speed of sound to be 340 m/s. Answer in units of m.

**chemistry**

What is the conjugate base of the following substances: a. (CH3)3NH /(CH3)3N b. H3N-CH2-COOH / H3N-CH2-COO c. H3N-CH2-COO / H2N-CH2-COO d. OOC-CH2-COOH / OOC-CH2-COO e. OOC-CH2-COOH / HOOC-CH2-COOH

**Algebra**

kewl

**Algebra**

Why is it necessary for the encoding function to be one-to-one?

**mathematics**

1/3 + 1/6 = simplify it later i need explanation of how you get this for example 3/4 + 1/8 = 3/4=6/8 6/8 + 1/8= 7/8 how did they get 6/8 im confused thanks for helping and please.

**Algebra**

A size 36 shoe in France is size 3.5 in England. A function that converts shoe sizes in France to those in England is g(x)= 3x-94/4. A size 6 shoe in the United States is size 3.5 in England. A function that converts shoe sizes in England to those in the United States is f(x)=...

**science**

thanks drwls :)

**science**

This biome extends across Canada and down the Sierra Nevadas and Rocky Mountains. It has large coniferous forests. This biome is the _____. a) desert b) grassland c) tundra d) taiga e) deciduous forest I PICKED D

**science**

All the following are conservation practices, EXCEPT______? a) reducing consumption b) reducing production of goods using the resource c) recycling d) restoring the environment e) reducing waste I PICKED D

**science**

When cold air moves below warm air (which rises), we feel _______, depending on how fast the air moves. a) an earthquake or earth tremor b) a drizzle or rainstorm c) a breeze or wind d) a tornado or thunderstorm d

**physic**

--

**algebra**

solve by elimination 3x+4y=2 6x+8y=4 stuck!!

**math**

Find y '. y = (2x^3 + 6)(2x^7 - 3)?

**COM 220**

nEED HELP WITH A FULL SENTENCE OUTLINE ON MEDIA VIOLENCE

**Aleg**

In 1991, the life expectancy of males in a certain company was 68.2 years. In 1997, it was 70.7 years. Let E represent the life expectancy in year t and let t represent the number of years since 1991. 1) The linear function E(t) that fits the date is E(t)=____t+____ Round to ...

**Math help please!!!**

edit: should be 3p^2q(1+3q-4q^2)

**Math help please!!!**

Factor completely 3p^2q + 9p^2q^2 - 12p^2q^3 I have done the following: 3p^2q(1+3q-4q^) but then i get stuck..not sure if that's the final answer..

**economic**

Rational people think at the margin that is one of the principle that I pickplay a major role out so can you provide an example for each about decision making interaction and the working of the economy.Explaine how that influences the marginal benefits and marginal costs ...

**economic**

which of the 10 principle do you think play a major role in your decision Provide an example for each about decision making interaction and the working of the economy.Explain how that influences the marginal benefits and marginal costs associated with the decision to purchase ...

**Math**

Use mathematical induction to prove that 5^(n) - 1 is divisible by four for all natural numbers n. Hint: if a number is divisible by 4, then it has a factor of 4. also, -1 = -5 +4 This is a take home test so I don't want the answer because I want to know how to do it. this...

**math**

1)In the figure, the vertices of right-angled isosceles triangle ABC are A, B(2,0) and C(8,0) respectively. find the equations of AB and AC 2)If the x-intercept and y-intercept of the straight line L: B(y-2) =Ax+8 are -8 and 3 respectively, find a)the value of A and B b)the ...

**math: not sure how to figure out**

Suppose a coin is biased so that it has the probilities below for landing on heads or tails on a single toss of the coin. P(h)=0.5020 P(t)=0.4980 If this coin is tossed twice find the probability P(hh)

**Chemistry**

The vapor pressure of nitrogen at several different temperatures is shown below. Temperature Pressure () 65 130.5 70 289.5 75 570.8 80 1028 85 1718 Use the data to determine the heat of vaporization of nitrogen. Determine the normal boiling point of nitrogen.

**chem**

Can someone help me I need to find out how to solve the following equation What is the PH/POH of a .0727m H3O+ Solution at 25 degrees c

**Chem**

The density of an unknown metal is 8.94 g/cm^3 and its atomic radius is 0.126 nm . It has a face-centered cubic lattice. Find the atomic weight of the unknown metal.

**chem**

Why are titrations using permanganate performed in acid solution?

**chem**

Why are titrations using permanganate performed in acid solution?

**chem**

Why are titrations using permanganate performed in acid solution?

**chemistry**

hmmmm this doesn't seem to help

**chemistry**

If this "point" for a particular titration occurs at pH x, a good indicator for for the titration would be indicator. Note: Provide only 1 indicator name (even if there are other indicators possible) and make sure the spelling is correct. X indicator 0.9

**Chemistry**

45.0 ml of 9.0x10 the negative 2m hno3 I am needing the steps to help solve the above chem equation

**chemistry**

If the stockroom fails to dry the KHP to remove the waters of hydration, the student's calculated concentration for the standardized base will be (low, high, or unaffected) A drop of NaOH is hanging from the buret tip before the titration of KHP. Once the student begins ...

**Chemistry**

question from my previous post answered by DrBob - is this because this acts as a polyprotic acid, or because the ratio in the Henderson Hasselbach for HA/A- remains the same?

**Chemistry**

is this because this acts as a polyprotic acid, or because the ratio in the Henderson Hasselbach for HA/A- remains the same?

**Chemistry**

How would the pH differ for a 0.1M solution of NaHCO3 vs 0.2M NaHCO3 - remain the same, double, half,or can't be calculated without Ka or Kb?

**math**

According to the Journal of Irreproducible Results, any obtuse angle is a right angle! Here is their argument. Given the obtuse angle x, we make a quadrilateral ABCD with DAB = x, and ABC = 90◦, andAD = BC. Say the perpendicular bisector toDC meets the ...

**math**

According to the Journal of Irreproducible Results, any obtuse angle is a right angle! Here is their argument.

**math**

Show that there are no positive integers n for which n4 + 2n3 + 2n2 + 2n + 1 is a perfect square. Are there any positive integers n for which n4 +n3 +n2 +n+1 is a perfect square? If so, find all such n.

**Chemistry**

Why is it important to use liquids with relatively lower boiling points when using the Dumas method?

**Chemistry**

How do you know that the NaCl has 100 ml. How much volume does the water which is also a product have?

**Chemistry**

How do you determine the moles of just NaCl? and is the moles of HCl and NaOH just the molar mass? Thanks

**MAth**

f(x)=x^2-9x+3

**MAth**

f(x)=x^2-9x+9

**History**

WHy ere the women in ancient egypt better off than the women in ancient greece? THANKS, HELP

**Chemistry**

Problem: In a first order decomposition reaction, 50% of a compound decomposes in 10.5 minutes. What is the rate constant of the reaction? The solution my professor gave says: k = .693 / 10.5min Where did the .693 come from? Thanks

**college STATISTICS**

Sample of 80 people randomly asked in casino shows that average lost per person is $160 with a standard deviation ó = $40. Based on this data create a 99% confidence interval for population mean. Does loss of $180 for single person contradict expectation? Explain your ...

**Math**

An urn contains 4 green, 6 blue and 10 yellow chips. You pay $5 to draw a chip from the urn. Here are the rules of the game: if you draw a green chip, the dealer returns you your bet and gives you an additional $5. if you draw a blue chip, the dealer returns you your bet and ...

**Physics**

An army of armadillios is attacking Cosine Castle where the coyotes reside. If an army must clear the 45 meter walls by 5 meters, at what angle must they set their cannons (from the horizontal) in order to fire inside the castle walls? The cannons fire cannonballs at 50 m/s. ...

**Business**

thnx:D

**Business**

Make sure to identify: • Your expectation of use of research by you in the workplace (ie: user, researcher, contributor) May i knoe what this quesiton is asking!!! thnx

**english!**

THNX.:D

**english!**

Write a short analysis of the use of researching in your future industry – how do they gather or use research ie: types of projects, proposals, etc… -can u explain this question to me plz. are they asking me to write a paragraph explaing how do they do research and ...

**Math**

a) What is Agnessa's hourly rate of pay in a year with 26 biweekly paydays? b) Using your hourly rate computed in part a), what would Agnessa's gross earnings be for a pay period working an extra 10 hours overtime paid 1.50 times the regular rate of pay? (should be ...

**7th grade math**

can you help me ms.sue

**math**

plzzzzzzzzzzzzzz help me

**math**

tim and jim shared 35$ in the ratio 4:3 .how much did tim get ?

**math**

amy sloved 3/5 of her math problems and had 24 left to do. how many problmes did she solve ?

**science**

thank you so much for helping me.

**5th Grade Science**

oko;

**Earth Science**

Which of the following help create volcanoes? plate tectonics landslides cracks in Earth's crust built up magma

**Physics**

A merry-go-round accelerates from est at .870 rad/sec^2. When the merry-go-round has made 4 complete revolutions, how much time has elapsed since the merry-go round started? What is the angular velocity of the merry-go round? Could someone help, please

**6th grade math**

you don't know that we are learning that in 5th grade

**Physics**

Starting from rest Maria pulls horizontally on her new wagon for 1.1 seconds. She exerts a constant force of 89N against a frictional force of 43N. The wagon's final velocity is 3.2m/s. If she is on a level ground, how much does the wagon weigh?

**Math 117**

it takes 4 hr for 8 cook to prepare a dinner. how long would it take for 7 cooks? inverse or direct variation?

**Algebra 2**

2. Biologists want to set up a station to test alligators in the lake for West Nile Virus. Suppose that the costs for such a station are $2,500 for setup costs and $3.00 to administer each test. a. Write an expression that gives the total cost to test x animals.

**algebra**

5+5x<40

**algebra**

im not good at algebra is it 4

**algebra**

8x-(4x+6)=2 the solution is x=

**algebra**

0.4x+4<0.8x-7 the < has a line under it im supposed to put a inequality symbol and the rest of the answer

**algebra**

so the answer this whole time is 6?

**algebra**

a+b for a=34 and b=2 ____ 6 a+b= ______ 6 i don't get this

**algebra**

is there a solution to this promblem? 9x+3y=-60 -9+y=76 help please??

**acc/220**

Write a 350- to 700-word paper describing a balance sheet, an income statement, a retained earnings statement, and a statement of cash flows. How does a company use these financial statements to make future business decisions? Use and define the following terms in your paper ...

**algebra**

but it says the y intecept is (0, something

**algebra**

find the slope and the y intercept y=3.1x-9 the slope is the y intercept is help thank you

**physics**

An analyzer is rotated about an incident ray. The intensity of light is found to increase and decrease, but it does not become zero at any point. The incident light is: a.partially polarized b.plane-polarized c.polarized in two planes d.unpolarized

**math**

How many 2s are there in 7

**algrebra**

10-3y-7y<30 the solution set is {y/y>= } i dunno how to do this?

**HELP**

So I do I find the phase shift based off this?

**fallacies**

Need help with two questions 8. From a letter to the editor: “The counties of Michigan clearly need the ability to raise additional sources of revenue, not only to meet the demands of growth but also to maintain existing levels of service. For without these sources those ...

**algebra**

im not to good at algebra so here goes im supposed to multiply 5.(3.2) i know im supposed to multiply both sides by 5 but be on that im not sure what to do help please?

**physical science 8th grade**

Copper has 2 known isotopes: ^63CU atomic mass= 62.9298 and ^65 CU atomic mass=64.9278. The average atomic mass of copper is 63.546 amu. Calculate the fraction(percent) of each of the 2 isotopes of copper

**algebra**

1 - 11 its supposed be like that