# Posts by Jack

Total # Posts: 1,848

Math
I'm after understanding more than an answer but an answer would be greatly appreciated. The question reads as "On the answer sheet for this question is shown an x-y graph of the function [y(x)=x^2cos(3x)] Add to that same picture a rough sketch of the graph of dy/dx ...

Maths
I'm after understanding more than an answer but an answer would be greatly appreciated. The question reads as "On the answer sheet for this question is shown an x-y graph of the function [y(x)=x^2cos(3x)] Add to that same picture a rough sketch of the graph of dy/dx ...

math; distributive property;perimeter of a triangl
use the distributive property to write an equivalent expression for the perimiter of the trangle?

science
need to identify the elements, compounds and mixtures of the iron and sulpher reaction.

Biology
Action potentials: Tick the box next to the ONE answer you believe is TRUE. A. compound action potentials increase in amplitude as the stimulus strength is increased. B. ONE action potential takes in the order of 1-2 seconds to be observed. C. generation decreases the Na+ ...

math
the curve y=x^2 - 3x - 4 cross the x-axis at P and Q. the tangent to the curve at P and Q meet at R. the normals to the curve at P and Q meet at S Find the distance RS?? please help i have honestly tried and have had no luck :)

math
the curve y=x^2 - 3x - 4 cross the x-axis at P and Q. the tangent to the curve at P and Q meet at R. the normals to the curve at P and Q meet at S Find the distance RS?? please help i have honestly tried and have had no luck :)

english
Please correct my english! Hello everybody! I'm not an english speaker, but currently study english at school. Our homework is to write an english dissertation. But before it, we should give the teacher the detailed plan. It's noted, so I will be very thankfull if ...

us history
what is a social contract?

Science
15/58

derivative
Anonymous is wrong, don't use that. bobpursley and I are correct.

derivative
Is that the 5th root of (3+5x+x^3)? If so, you can rewrite it as (3+5x+x^3)^(1/5). You have to use the chain rule to find this derivative. First set (3+5x+x^3)=z. You know have z^(1/5). Take the derivative of this. (1/5)z^(1/5-1)=(1/5)z^(-4/5). Now substitute (3+5x+x^3) back ...

chemistry
One way that safety enters into specifications is to specify the composition of a vapor in air that could burn if ignited. If the range of concentration of benzene in air in which ignition could take place is 1.4 to 8.0 percent, what would be the corresponding temperatures for...

physics
What gravitational force do the two protons in the helium nucleus exert on each other? Their separation is approximately 1.0 {\rm fm}.

marketing research
is a random sample of 500 students large enough to represent all of the full time college students in the united states?

grammar
I'm trying to figure out how this sentence should be correctly punctuated. He soon found out that it was just what it was called, a dream. Specifically, I'm questioning the comma after called.

PHYSICS
Two satellites A and B are in different circular orbits about the earth. The orbit speed of satellite A is three times that of satellite B. Find the ratio (TA/TB) of the periods of the satellite.

phsyics
Each of the space shuttle’s main engines is fed liquid hydrogen by a high-pressure pump. Turbine blades inside the pump rotate at 617 rev/s. A point on one of the blades traces out a circle with a radius of 0.020 m as the blade rotates. (a) What is the magnitude of the ...

calculus
Find the relative extrema of f(x) = -2x^2 + 4x + 3 I don't know how to use the First derivative test to find it.

chem
a molar elipticity [q]466 nm, 25 C of D(−) − Co(en)3I3.H2O and obtained -5940 deg.cm2.decimol-1. Calculate the elipticity angleq (in mdeg) assuming they dissolved 0.25 g sample in 5 mL of H2O and used a 1 x 1 cm cuvette. (

Chemistry
210

physics
in a tug of war a jeep of a mass 1400kg and a tractor of a mass of 2000kg pull on a horizontal rope in opposite directions. at one instant, the tractor pulls on the rope with a force of 1.50*10^4N while its wheels push horizontally against the groud with a force of 1.60*10^4N ...

Organic Chemistry
In the substitution reaction of 2-pentanol with sulfuric acid and sodium bromide, how many grams of sodium bromide and mL of sulfuric acid would be required if we use 3.5 grams of 2-pentanol?

Chemistry
the activation energy for the decomposition of HI(g) to H2(g) and I2(g) is 186kj/mol. the rate constant at 555k is 3.42 x 10^-7 L/mol*s. What is the rate constant at 645K? Please Show all Steps! thank you!

Maths
Find all the roots of the equation Sin(2x)=1/2 in the range of -pi<x<pi giving answers in radians as multiples of Pi

Science
Help!! How many atoms in 3.45 mL of water? (H2O only;mL=g) and If you are out panning for gold and discover a nugget that is exactly 2.50 moles, how many molecules, atoms, and grams would you have? At a cost of \$375 per ounce, what would be the value of gold?

stat
Microbes in a certain colony exposed to radiation have a 1=6 chance of being mutated. a. If ten microbes from the colony are sampled, what is the probability that exactly 4 will be mutated? b. If ten microbes from the colony are sampled, what is the probability that at most 4 ...

Chemistry
50 mL of Water Ti = 20C Tf = 45C d = 1.00 g/mL C = 4.184 J/g * C 50 mL * 1.00g/mL = 50 g Delta T = 45-20 = 25 C q = m * C * T = (50) (4.184) (25) = - 5230 J -5230/-82800 = 0.061 mol Molar mass of CaCl2 = 110.98 g/mol 0.061 mol * 110.98 g/mol = 6.77 g

What is the rule for this function? Input 1, 2, 4, 5, 10, 12 output 3, 5, 9, 11, 21, 25

Calculus
A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.

Calculus
A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.

science
a microscope has two types of these

science
a microscope has two of these

math
how do you show that line 3x+y-2=0 is a tangent of the curve y=(4x-3)(x-2) and how to find the point of contact??

stats
yes.. good job

mathmath
A study conducted by the Metro Housing Agency in a midwestern city revealed the information below concerning the age distribution of renters in the city. (Round your answers to four decimal places.) Age Adult Population, % Group Who Are Renters, % 21-44 53 64 45-64 29 43 65 ...

Algebra
Determine the number of terms in the expression 14m - 16.

She will become a physicist one day. Have to identify the verb or verb phrase and then tell if it contains a linking verb or does not. will become=verb phrase contains linking verb

calculus
Find the 1st derivative of the function: y = 1/4 sin^2 (2x) So confused...

Math
what is the prime factorization of 72

math
A(-1,-2) B(7,2) show that the lenght AB may be written in the form p root5 wjere p is an integer to be found?? is then ans just 4root5?? if not hep please thenks

Math
make up a data set of at least 12 numbers that have the following landmarks. maximum 18 mode 7 range 13 median 12

physics college
Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.

Physics
Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.

chemistry
the molar mass of a newly synthesized jluorocarbon was measured in a gas microbalance, This device consists of a gkass bulb forming one end of a beam, the whole surrouned by a closed container. The beam is pivoted and the balance point is attained by raising the pressure of ...

Science
How are the structures in genetics related?

Science
How do you represent data in a graph?

chemistry
A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!

math
How do i show work for this math question. A puppet requires 3/4 yard of material. How many puppets can be made from 9 yards of material?

Chemistry
H2O (l) requires the largest amount of energy to raise the temperature of 25.0g H2O of the substance from 15.0 *C to 37.0 *C. Calculate the energy. Hg (l) has the largest temperature change when 550 g of the substance absorbs 10.7kJ of energy. Calculate the temperature change...

Chemistry
A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!

physics
A picture hangs on the wall suspended by two strings, with è = 61°. The tension in string 1 is 1.8 N. è is connected to string 1, and 32° is connected to string 2. (a) Is the tension in string 1 greater than, less than, or equal to the tension in string 2...

physics
please help! physics doesn't click with me. thank you for your help! A 23 kg suitcase is being pulled with a constant speed by a handle that is at an angle of 25° above the horizontal. If the normal force exerted on the suitcase is 155 N, what is the force F applied to...

Chemistry
For every liter of sea water that evaporates, 3.70g of magnesium hydroxide are produced. How many liters of sea water must evaporate to produce 5.00 moles of magnesium hydroxide? Please show and explain all steps! Thank you!

math
Marcus want to make a stone walkway in his garden.the rectangular walkway will be 3 feet wide and 18 feet long.Each 2-foot by 3-foot stone covers an area of 6 sq. feet.How many stones will he need? is it 9?

calculus
Verify that the Intermediate Value theorem applies to the indicated interval and find the value of c guaranteed by the theorem. f(x) = x^2 - 6x + 8, [0,3], f(c) = 0 I have no idea how to use the theorem :(

science
What is the chemical name for Polyurethane and what does it look like at it's resting state?

Avon k 8 Center
If 50 is the first number, what is the second number?

Next, Tom remembers that he heard a doctor talking about something that takes two weeks to heal. I have to identify what type of pronoun that (second one in sentence) is. Would it be a relative pronoun?

Chemistry
ammonia gas reacts with copper (ii) oxide at high temperatures to produce elemental nitrogen, copper metal, and water vapor. Assume that 36.2g ammonia reacts with 180.8 g copper ii oxide. (balanced equation: 2 NH4 (ammonium) (g) + 4 CuO (copper ii oxide) ==> N2 (nitrogen ...

Chemistry
Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

Chemistry
Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

Chemistry
61.0 mL of a 1.50 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 167 mL of water. What is the final concentration?

calculus
Fond the limit of lim x -> 3 [1/(x+4)] - (1/4) _________________ x

Chemistry
DDT, an insecticide harmful to fish, birds, and humans, is produced by the following reaction: 2 C 6 H 5 Cl (Chlorobenzene) + C 2 H O Cl 3(chloral) ==> C 14 H 9 Cl 5 (DDT) + H 2 O In a government lab, 1142 g of chlorobenzene is reacted with 485g of Chloral. A)What mass of ...

physics
A hot air balloon has just lifted off and is rising at the constant rate of 1.8 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.2 m/s. If the passenger is 2.5 m ...

physics
An astronaut on Neptune drops a rock straight downward from a height of 0.95 m. If the acceleration of gravity on Neptune is 11.2 m/s2, what is the speed of the rock just before it lands? (m/s)

Math
State the Domain and show work. y = x + 2 / x^2 - 4x - 12

MATH
26=6(5-6A)

calculus
Find all possible radii of circle centered at (3,6) so that the circle intersects only one axis

calculus
Solve: sec(x)^2= 3tanx +1 *** It is suppose to be the sqaure root of 3 but i could find the symbol so just wrote the 3 without it but it is suppose to be the square root of 3 times tanx + 1

math
256 + 1,273

PRE CALCULUS
the question is actually square root of ( x+5) = x please ANSWER

PRE CALCULUS

Pre CALCULUS

Pre Calculus
As x increases from p/4 to 3p/2, the value of sin(x) : A.increases throughout the interval B.decreases at first, then increases C.increases at first, then decreases D.decreases throughout the interval E.none of the above please explain why the answer is as it is, I don't ...

Calculus
Solve for x: lnx^3 - 2lnx = 1 Please try and show how you got the answer best as you can thank you :)

Calculus
Solve : sec^2(x)= ã3*tanx + 1 on [0,radian-180 degrees) - couldn't find the symbol for radian on computer please try and explain how you got your answer best as yu can thanks so much :)

Calculus
The normal body temperature in humans ranges from 97.6 degrees fahrenheit to 99.6 degrees fahrenheit. Concert this temperature range into degrees celcius

Calculus
The celcius scale is devised so that 0 degrees celcius is the freezing point of water ( at 1 atmosphere of pressure) and 100 degrees celcius is the boiling point of water ( at 1 atmosphere of pressure) . If you are more familiar with the Fahrenheit scale, then you know that ...

Chemistry
A single 4p orbital can hold how many electrons? i got 6 is that correct or no? Would conducting electricity be considered a physical or a chemical property of ZINC?

rounding
(a) 455 cal to joules thats 1 903.72 joules but i need to round it to 3 sig figs how do u do that?

plz help me for math
you always want to start by putting like terms together. So why don't you do that first and then its really easy from there all you have to do is follow the signs(- or +) and add or subtract

chemistry
Would Conducting electricity be considered a physical or chemical property of zinc i got physical but just want to make sure.

Chem
Would conducting electricity be considered a physical or chemical property of ZINC i got phyiscal but just want to make sure.

chemistry
A single 4p orbital can hold how many electrons? i got 6 is that correct or no?

Pre Calculus
Determine the coordinates of the point (xy) where the curves y=(12)x−5 and y=x2+2x−15 intersect in the third quadrant

Pre Calculus
The strength of a cable is proportional to the square of its diameter. If a 2-cm cable will support 800kg, how much will a 3-cm cable support?

chemistry
A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

chemistry
Which of the following properties is a chemical property of phosphorus? Answer a) it burns in air b) it is a white waxy solid c) it melts to form a viscous liquid at 44.1 oC d) Both a and c are both examples of chemical properties. e) a, b, and c are examples of chemical ...

chemistry
Convert a density of 2.74 x 103 g/L into a density with dimensions of kg/mL. please show how would this conversion be done.??

physics
A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

Mayans and aztecs
how did the aztecs acquire most new pieces of land

Chemistry
Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

Chemistry
Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

math
find the range of the function. g(x) = 5 + (square root of) (4 - x) please show all steps.

Math
Solve the following equation. 4.7 = 1.13x^2 Do i square root the 1.13x^2 first? or divide both sides by 1.13?