# Posts by Matthew

Total # Posts: 681

**English**

Writeacher, can you suggest possible topics for email conversations among teenagers? 1) I will ask my students to introduce themselves, describe their daily routines, their hobbies and interests and the place where they live. They will do that with the help of our arts teacher...

*March 13, 2012*

**English**

I urgently need you to help me find the proper words. Thank you Writeacher 1) Thank you very much for sending me the list of your students. I was thinking of creating a link to our partnership ( I don't know how to express this) on my school webpage. 2) Five of your ...

*March 13, 2012*

**English**

Writeacher, here is my today's post. I varied my name from Henry to Matthew because there are too many Henry on Jiskha!!! In this way I can get to my post more easily. Imagine you have been on holiday with your family. Write an email to a friend telling him/her all your ...

*March 13, 2012*

**Calculus-derivatives**

Verify if these are correct answers. 1. The derivative of f(x)=e^2x -e^-2x is f'(x)=2e^2x - 2e^-2x? 2.A certain radioactive substance is decaying so that at time t, measured in years, the amount of the substance, in grams, given by the function f(x)=3e^-3t. What is the ...

*March 6, 2012*

**Chemistry**

So for #2 it should be 2Pb(NO3)2 → 2PbO2 + 4NO2 + O2 #4, maybe instead of SO3 on the products side, it should be SO4? So, 4NaCl + 2SO2 + 2H2O + O2 → 2Na2SO4 + 4HCl

*February 20, 2012*

**Chemistry**

So, they give me a word equation, where I am suppose to try and create a balanced equation for it. Ammonium phosphate and barium hydroxide react to form ammonium hydroxide and barium phosphate. 2(NH4)3PO4 + 3BaOH2 → 6NH4OH + Ba3(PO4)2 [I was thinking there should be ...

*February 20, 2012*

**Chemistry**

I need some help with some of these questions: The action of bacteria on meat and fish produces a poisonous compound called cadaverine. As its name implies, it stinks! It is 58.77 percent carbon, 13.81 percent hydrogen, and 27.40 percent nitrogen. Its molecular weight is 102.2...

*February 20, 2012*

**Chemistry**

I need some help with some of these questions: The action of bacteria on meat and fish produces a poisonous compound called cadaverine. As its name implies, it stinks! It is 58.77 percent carbon, 13.81 percent hydrogen, and 27.40 percent nitrogen. Its molecular weight is 102.2...

*February 20, 2012*

**Calculus**

How many tangents does the graph of f(x)=(x-1)^2(x-3)^2 have? I found out the derivative of f(x)=(x-1)^2(x-3)^2 f'(x)=4x^3 - 24x^2 + 44x -24 What do I do next?

*February 18, 2012*

**algebra**

Hi, Lucy, this is Matthew's mom, if you put the three corners together you would get 1/2 a circle or circumference. I hope this helps you.

*February 14, 2012*

**Math**

Mr. Clarkson and Mrs. Rose had an average of $180. After Mr. Clarkson spent $73 and Mrs. Rose received $38 from her father, Mr. Clarkson had 1/4 as much money as Mrs. Rose. How much money did each have at first?

*February 14, 2012*

**Calculus**

Could someone help me with this question. Determine what limit would be represented by the following graph. imgur dot com/bceWN I am not sure if it has open dot or closed but what would the equation be for open and closed dot?

*February 12, 2012*

**Calculus**

Is this the right explanation for this question 1. Examine the continuity of the function h(x)= -x, if x<0 0, if x=0 x, if x>0 Answer: Since h(x)= -x, if x<0 0, if x=0 x, if x>0 is h=|x|, we can conclude that the function is 1. continuous everywhere 2. ...

*February 11, 2012*

**Calculus**

I don't know what to write for question b and c. 1 a)Determine the values of x for which the function f(x) = 3/(√x^2+3x-4) is continuous. Values of x are -4 and 1. -------------------------------------- b) What does your answer in part a. represent? c) Why is it ...

*February 11, 2012*

**Math/trig**

Log radical b/ a^2 is equivalent to 1) 1/2 log b + 1/2 log a 2) l/2 log b- 2 log a 3) 2 log b - 1/2 log a 4) 1/2logb/2 log a

*February 11, 2012*

**Calculus**

Verify this question 1. Determine lim as x->3 (3x-8)/(4x-12), if it exists. (3(3)-8)/(4(3)-12) =1/0 Therefore it doesn't limit doesn't.

*February 11, 2012*

**Calculus**

Is there suppose to be calculations involved? :|

*February 11, 2012*

**Calculus**

What would be discontinous at x=? explain please

*February 11, 2012*

**Calculus**

Can someone help me with this question. With steps. Examine the continuity of the function h(x)= -x, if x<0 0, if x=0 x, if x>0

*February 11, 2012*

**Math**

Can You please explain the steps

*February 10, 2012*

**Math**

Determine the values of x for which the function f(x) = 3/(√x^2+3x-4) is continuous.

*February 10, 2012*

**Precalculus**

I got 4x^3+8x^2+5x+1/(x-3)

*February 1, 2012*

**Precalculus**

I keep getting wrong answer for this question. Write as a single logarithm log(x+1)+2log(2x+1)-log(x-3)

*February 1, 2012*

**Precalculus**

I keep getting wrong answer for this question. Write as a single logarithm log(x+1)+2log(2x+1)-log(x-3)

*February 1, 2012*

**Precalculus**

I keep getting wrong answer, its not the same as the book :3

*February 1, 2012*

**Precalculus**

Write as a single logarithm log(x+1)+2log(2x+1)-log(x-3)

*February 1, 2012*

**Math**

solve for x 2^x=0.125 5^2x=39 13^x=27

*February 1, 2012*

**Math**

THANK YOU I HAVE BEEN ON THIS FOR SO LONG

*January 31, 2012*

**Precalculus**

Evaluate log(base4)8 + log(base4)(1/8 log(base4)=(8x1/8) =1 I got 1 but the back of the book says 0...?

*January 30, 2012*

**Physics**

Your friend's car is parked on a cliff overlooking the ocean on an incline that makes an angle of 16.9° below the horizontal. The brakes fail, and the car rolls from rest down the incline for a distance of 36.3 m to the edge of the cliff, which is 61.1 m above the ...

*January 28, 2012*

**English**

Is Famine considered as Extra curricular activity?

*January 23, 2012*

**English**

I am doing my application form for a university, it asks for my job information Job Title: I work at Mcdonalds part-time and work in the kitchen, what will my job title be? Kitchen staff? :S

*January 22, 2012*

**Math**

Evan is painting a stool that has a cylindrical seat and four rectangular prism legs. The seat has a diameter of 8 inches and a height of 2 inches. Each leg is 2 inches by 2 inches by ten inches. How much area will Evan have to paint? Use three point one four for pi. Show your...

*January 20, 2012*

**stats**

The null hypothesis in this study where μ1 = tv news group, and μ2 = radio news group is

*January 11, 2012*

**Math**

Total number of scores is 45. Alex scored 9. What percent of the total number of points did Alex score?

*December 30, 2011*

**Calculas**

(Inventory Cost) A shopkeeper finds that the cost C of ordering and storing the latest laptop is C = 2 x + (300000 / x), where x is in the interval [1, 300]. The delivery of truck can bring at most 300 units per order. (a) Find the order size that will minimize the cost (b) ...

*December 16, 2011*

**Caculas**

(Airplane & Radar) An airplane is flying (horizontally) at the height of 6 km on a flight path that will take it directly over a radar tracking station (on ground). If the distance D between the plane and the radar is decreasing at a rate of 300 km/hr, find the speed of the ...

*December 16, 2011*

**Biology**

Using RNA a s a template for prot e in synthesis instead of t r ans l a t ing prot e ins directly from the DNA is advantageous for the cell because A) RNA is much more stable than DNA. B) RNA acts as an expendable copy of the genetic material, allowing the DNA to serve as a ...

*December 11, 2011*

**Calculus**

Find the area of the region bounded by y=x^4/3-4 , the x-axis,x=-1 , and x=1 .. Search tips:

*December 8, 2011*

**MATH**

can you help me with the table and graph for a direct and indirect equations? Y=x Y=x+5

*December 8, 2011*

**science**

like what?

*December 7, 2011*

**science**

are there any current or new treatments available for epilepsy?

*December 7, 2011*

**science**

What is epilepsey?

*December 7, 2011*

**Physics**

An electric motor rotating a workshop grind- ing wheel at a rate of 147 rev/min is switched off with a constant deceleration of 1.24 rad/s2. How long does it take for the grinding wheel to stop? Answer in units of s Through how many radians has the wheel turned during the ...

*December 6, 2011*

**Chemistry**

Calculate the heat (in kJ) required to transform 58.60 g of dinitrogen tetraoxide from a solid at a temperature of -9.3 °C to a gas at 47 °C. Report your answer to one decimal place. Data: Molar mass of dinitrogen tetraoxide, N2O4 = 92.011 g/mol Melting point = -9.3 &...

*December 5, 2011*

**Chemistry**

(a) Which of the ions K+ , Na+ , Be2+ will have the largest heat of hydration? Which the smallest? (b) Of the two compounds KNO3 and NaNO3 , which has the stronger intermolecular forces? (c) Of the two compounds PCl3 and Xe, which has the stronger intermolecular forces?

*December 5, 2011*

**Statistics**

its a worksheet where i have to do the hypothesis tests though.

*December 3, 2011*

**Statistics**

Hi. I need to complete hypothesis tests and i am unsure if i used the correct tests for each of the following: 1. Do people actually prefer Pepsi or Coke in a taste test? 2. Can people correctly identify Pepsi versus Coke? 3. Are people consistent with their prior preference? ...

*December 3, 2011*

**trig**

for what values of theta between 0 and 2 pi is the function of theta equal sine theta positive?

*November 30, 2011*

**Superglue fuming--fingerprints**

What is an amino acid? Why do they cause superglue to stick to my fingerprints on a cd when I place the cd in a plastic box covered with plastic wrap? I'm 9, so I really need just a simple answer. Thanks.

*November 7, 2011*

**Chemistry**

How many molecules (not moles) of NH3 are produced from 8.92×10−4 g of H2?

*November 6, 2011*

**math**

out of 150 students, 20% of them earned straight A's. how many students earned straight A's?

*November 3, 2011*

**math**

determine the value of N: N/20 * 100%=60%

*November 1, 2011*

**Math**

There are 80 students 35 of them are boys about what percent are boys

*October 30, 2011*

**Math**

Thanks

*October 23, 2011*

**Math**

Which of the following is NOT proportional? A)4/10 = 6/15 B) 2/1 = 30/15 C) 5/25 = 4/24 D) 63/90= 70/100

*October 23, 2011*

**jlc**

Three is the first number of pair and 8 is second if 50 is first number what is second number?

*October 20, 2011*

**4th grade math**

you simply have to write it out. So first one the expression would be 1285-622 because have to find the difference between the two numbers.

*October 18, 2011*

**geometry**

The way to work out this problem is that you do the lXhXw so width times the height times the length so 6 times 6 times 6= 216. 5th grader by the way.

*October 18, 2011*

**7th grade subject**

you simply must chose whether which one makes sense so I would go with5-3=2

*October 18, 2011*

**Proof read please**

You should divide the paragraphs so it will look a whole lot neater. Rather than that I think it's good.

*October 15, 2011*

**English**

take out ( ).

*October 15, 2011*

**physics**

suppose an experimental arrangement like the one in part 2 has mass m1= 0.200kg at the 0.100m mark and a mass m2=0.100 kg at 0.750m mark. Can the system be put in equilibrium by a 0.050kg mass? if it can not be done state where it would be placed. If it cannot be done, state ...

*October 13, 2011*

**Chemistry**

Thank you so much for the help on my other question!!! An alloy (solution of metals) is 80% by volume iron. The rest is aluminum. Aluminum has a density of 2.70 g/cm³, and iron's is 7.87 g/cm³. A block of alloy measures 2.0 ft. wide and 3.0 ft. long. If the block...

*October 8, 2011*

**Chemistry**

An aqueous solution of copper (I) chloride is 15.7% by mass copper (I) chloride. Copper (I) is 35.8% by mass chlorine. If the solution has a density of 1.045 g/cm³, how many gallons of solution contain 2.3 kg of copper?

*October 8, 2011*

**College Math**

I am really struggling with this Fibonacci number problem. If the greates common factor of "m" and "n" is "r", then the greatest common factor of Fm and Fn is Fr. Show that this is true for m=6 and n=9. I am so confused

*October 2, 2011*

**math**

there are two planes. they both leave the airport at 1pm. one plane travels north at 150mph and the other plane travels west at 200mph. how many miles will they be apart at 3pm?

*September 28, 2011*

**Algebra**

19[7+w+(-2)]

*September 26, 2011*

**Algebra**

How far in miles is a line of 1,000,000 pennies. Please show chart with 5 instances. Define a variable and write an algebraic expression.

*September 11, 2011*

**calculus**

Find the derivative of the function. 1. 2x+5/3x-2 2. (1-x)(1+x^2)^-1 Please show work. TYVM. :)

*September 11, 2011*

**physics**

A plane flying horizontally at 50 m/s is 2000m from its target. a)At what height must a projectile be released in order to strike the ground target. (neglect air resistance) b)At what velocity will the projectile strike the target? c)What is the angle of impact with respect to...

*September 11, 2011*

**physics**

A rocket is fired at 1500 m/s at an angle of 50 degrees with respect to the ground. a)What are the horizontal and vertical velocities at 10 seconds. b)What is the actual velocity at 10 seconds.

*September 11, 2011*

**Math**

rays pq and qr are perpendicular. point s lies in the interior of <pqr. if m<pqs = 4x + 7 and m<sqr = 9 + 4a, find m<pqs and m<sqr

*September 5, 2011*

**economics**

Assume that it takes four hours of labor time to paint a room and three hours to sand a floor. If all 24 hours were spent painting, how many rooms could be painted by one person? If a decision were made to sand two floors, how many painted rooms would have to be given up? ...

*June 15, 2011*

**science**

how can pollution start in the Blue Ridge region affect the habitat of a tadpole living in the Piedmont region (think about the watershed)

*June 2, 2011*

**Algebra**

Can i get some help simplifying this fraction? ((x+5)/(x)) / ((x+5)/(2x))

*May 21, 2011*

**algebra**

The height above the ground of a ball thrown up with a velocity of 96 feet per second from a height of 6 feet is 6+96t-16^2 feet, where t is the time in seconds. According to this model, how high is the ball after 7 seconds? Explain (Thank you in advance! :)

*May 4, 2011*

**physical science**

list two safety procedures to create a supersaturated solution

*May 3, 2011*

**Chemistry**

I need to know how to right a net ionic equation for the following chemical reaction: 5 H2C2O4 + 3 H2SO4 + 2 KMnO4 = K2SO4 + 2 MnSO4 + 8 H2O + 10 CO2

*April 14, 2011*

**Calculus I**

Using Newton's Method, determine the first approximation to the solution of: e^(4x)= 10-2x starting with x=0 what is x1= ??? P.S. ( the 1 is a subscript )

*April 8, 2011*

**language arts**

from the following words I got to separate them into 3 groups: omitted syllable, omitted letter, and added syllable. drowned, restaurant, ivory, chocolate, desperate, lightning, adjective, penetrate, aspirin, athletes, identity , sisastrous, ecstatic, platinum, incidentally ...

*April 7, 2011*

**Physics 203 ( College)**

Tangential acceleration is the instantaneous linear acceleration associated with the particle at distance (r) from the center of rotation. thus Centripetal Accel= (angular accel)(r)

*April 4, 2011*

**Physics**

When friction is used to counteract centrifugal force, the side friction factor, f, between the tires and roadway is incorporated into the calculation for the superelevation angle. (the angle of road banking where friction is not needed) tan@=[(Vt)^2-(f)(r)g]/[(r)g+f(Vt)^2] (...

*March 29, 2011*

**physics**

An unstable atomic nucleus of mass 17.0 ¡Ñ 10¡V27 kg which is at rest disintegrates into three particles. One of the particles, of mass 5.00 ¡Ñ 10¡V27 kg, moves in the y direction with speed 4.50 Mm/s. Another, with mass 8.40 ¡&...

*March 28, 2011*

**algebra**

a sphere has a diameter of 6x cen write an expression to represent the volume of the sphere in terms of pie

*March 24, 2011*

**Chemistry**

What is the volume of 0.129 M HCl(aq) re- quired to neutralize all of the hydroxide ions in 46 mL of 0.216 M KOH(aq)? Answer in units of mL. Answer: 77.0232 What is the molarity of Cl− ions at the stoichiometric point? Answer in units of mol/L. What is the pH of the ...

*March 23, 2011*

**calculus**

find an equation of the curve that satisfies dy/dx=4x^3y and whose y-intercept is 7

*March 19, 2011*

**separation of variables**

solving the initial value problem by separation of variables dy/dx=(4(sqrt of y)lnx))/x, y(e)=9

*March 19, 2011*

**Geometry**

The sum of the measures of the angles of a polygon with n sides is given. Find n. 32) 180 33) 1080 34) 1980 35) 2880

*March 17, 2011*

**Math**

How to change 320% into a decimal and a fraction

*March 9, 2011*

**math**

patterns and equations: x: 0,3,__,10 y: __, 8, 12,15

*March 3, 2011*

**math**

150 = 25p

*March 2, 2011*

**History**

would an Egyptian style revolution beneficial or detrimental to the US government?

*February 22, 2011*

**geometry**

Angle GHJ and Angle IHJ

*February 22, 2011*

**math**

adding fractions with unlike denominators: 7/9 + 5/6?

*February 16, 2011*

**Geometry**

Given ABCD is a square AC= BD = 4 units Ac= BD pass origin of (0,0) Find coordinates of A B C D

*February 11, 2011*

**geometry**

Given ABCD is a square AC = BD = 4 units Find coordinates of ABCD

*February 11, 2011*

**Physical Science**

Suppose you dissolve 40g of potassium nitrate in 100 cm3 of water at 100 C. If half the solution os poured out, how many grams of potassium nitrate will the remaining solution contain?

*February 7, 2011*

**3rd grade math hw help!**

explain why 2/3 is greater than9/12

*February 3, 2011*

**math**

The area of a parallelogram is 100 square millimeters. The base is 4 milimeters. Find the height.

*February 3, 2011*