The homework help thread...(SERIOUS)

[vanbroeK]

I can't for the life of me remember how to find unknown powers.

I have come to 2=1.05^T

How do i find T? I know this is basic but cannot remember.

[Cell-Tech]

I can't for the life of me remember how to find unknown powers.

I have come to 2=1.05^T

How do i find T? I know this is basic but cannot remember.

ln2 = T*ln(1.05) --> T = ln2/(ln1.05)

[marky123]

insted of math do curls

[Cell-Tech]

insted of math do curls

lol is that aimed towards me?

[matz18]

lol is that aimed towards me?

i think so

[Cell-Tech]

i think so

I lift... I have 2 pictures posted, you have none. I work out and study a very math heavy subject... It's called being well rounded. I think I'll continue doing both

[iXander]

Anybody good at logarithmic or exponential equations? Got this on my study guide:

Determine the number of years ellie left her money in the bank if she started with $25 and ended with $165 in an account compounded monthly at interest rate of 2.5%.

So far I just made the model ( 165=25(1+0.025/12)^12t ), can't solve it though. Thanks guys

[yup123]

http://www.khanacademy.org/#browse

Check that website out brahs. I just discovered it today and it's amazing. This guy just basically posts videos on how to do just about anything school-related lol.

[yup123]

Anybody good at logarithmic or exponential equations? Got this on my study guide:

Determine the number of years ellie left her money in the bank if she started with $25 and ended with $165 in an account compounded monthly at interest rate of 2.5%.

So far I just made the model ( 165=25(1+0.025/12)^12t ), can't solve it though. Thanks guys

165-(25x2.5)=102.5


(102.5)(0.025)=2.5625

165-102.5=62.5

62.5/2.56=24

24/12=2

2 years me thinks

[Scott226]

Business Marketing and Operations, College/University level.

PM if you need help.

[Maxwell1995]

Need help solving quadratic equations by square roots.

The problem is: x^2-4x=5

Here's what I've done so far.

x^2-4x+4=5+4

(x-2)(x=2)=9
√(x-2)^2=√9
x-2= +or-3

x=+or-4+5

All I need now is the answer, but I'm not sure how to get it. Any suggestions?

[Cell-Tech]

Need help solving quadratic equations by square roots.

The problem is: x^2-4x=5

Here's what I've done so far.

x^2-4x+4=5+4

(x-2)(x=2)=9
√(x-2)^2=√9
x-2= +or-3

x=+or-4+5

All I need now is the answer, but I'm not sure how to get it. Any suggestions?

Not really sure what you did.

x^2-4x=5

x^2-4x-5=0 --> (x-5)(x+1)=0 --> x=5 and x= -1

[Maxwell1995]

Not really sure what you did.

x^2-4x=5

x^2-4x-5=0 --> (x-5)(x+1)=0 --> x=5 and x= -1

Thanks brah.

This will hopefully get me on the right track.

[jakeastanton]

thermochemistry is a witch. help me now!!!!????????

[BigChamp89]

thermochemistry is a witch. help me now!!!!????????

with wut?

[judowrestler1]

determine either the convergence or divergence of


using the comparison or limit comparison test

[usfbullsfan100]

ok guys i suck in comp 2, i need a good grade on this last project that we are doing, What we need to do is pick a problem in society, or local and talk about how you want to fix it what you need to do ect. my thing im going to do is obesity in America and how people should try becoming fit, does anyone have any scholarly or non scholarly (preferably scholarly) journals that talks about why people need to become fit, like the benefits of becoming fit, live longer, less health problems, etc thanks!

[lynkkkkk]

Vietnam War ****s report-in!


I've been researching for a couple of days on the following topic

"To what extent was the NLF ‘simply a tool of North Vietnamese communist expansion’ in the period before 1965?”.

I've got a lot of information on this. I'm just having trouble making up my own opinion. Anyone have any ideas?

My train of thought at the moment is that the NLF formed in the South to articulate the protests of the people suffering under Diem's anti-communist tirade. It was the voice of the peasants first, and sewed the seeds of communist second.



amidoinitrite?

[terahammer]

determine either the convergence or divergence of


using the comparison or limit comparison test

cannot use CT because its only for positive series. sin n takes positive and negative.
only learnt this today. all i can help lol

[Willaman]

ITT = Genius'.

[DonatelloBro]

Basically I have a Math Test on Tuesday. I know some of the exact questions, but tbh I try my best in the class but I just don't understand what's going on.

The exact questions I KNOW will be in the test are:

Graph the line y=x+3 using the intercept method.
Graph the inequality y>2x+4.
Show that the line 2x-y+3=0 passes through the points (0,3) and (-4,-5).
Find the perimeter of a triangle whose vertices are A (2,0), B (8,5) and C (4,0) include diagram.
Find the y intercept, x intercept, axis of symmetry, and coordinates of the vertex for the parabola y=x2-2x-8.

This shiat is hard as heck.

[Cell-Tech]

determine either the convergence or divergence of


using the comparison or limit comparison test

This made it apparent I'm rusty on some parts of calc 2 lol. I have to read up on all the different tests and when they're applicable.

It does converge though, do you need a specific value?

[AsianAesthetics]

Basically I have a Math Test on Tuesday. I know some of the exact questions, but tbh I try my best in the class but I just don't understand what's going on.

The exact questions I KNOW will be in the test are:

Graph the line y=x+3 using the intercept method.
Graph the inequality y>2x+4.
Show that the line 2x-y+3=0 passes through the points (0,3) and (-4,-5).
Find the perimeter of a triangle whose vertices are A (2,0), B (8,5) and C (4,0) include diagram.
Find the y intercept, x intercept, axis of symmetry, and coordinates of the vertex for the parabola y=x2-2x-8.

This shiat is hard as heck.

1. graphing the line of a linear function using intercept method.

note that linear functions are a straight line on a graph and they are to the power of 1 in equation form. so y=mx+b. your equation, y=x+3, is essentially y=1x+3. m=1, b=3.

b is the y intercept. meaning when the x cordinate is 0, the y point is b. so the y intercept is (0,3) for y=x+3. now, you have figured out one point on the graph. note that to draw a straight line, you need 2 points. we need to find the second point of the graph now. let's look for the x intercept (when y coordinate is 0, x coordinate is something). to find the x intercept, we plug in 0 for y. using basic algebra, you can find that the x intercept is (-3, 0). now, draw a straight line across these 2 points to find the graph.

*note that a + sign infront of x for y=mx+b signals the graph is incline, a negative sign signals the graph is decline.

*note that a multiplier infront of x, m, means the slope of the line. 2 means for every 1 increment in x, y increases by 2. 3 means for every 1 increment in x, y increase by 3 and so on.

2. to graph an inequality, we simply graph the same way we do for a normal linear graph. then we look at the the sign. if it's a bigger than sign, >, we shade the area of the graph above the line and the line is doted (draw the line with dots). if it's a less than sign, we shade the area below the line and the line is doted. if there's a less/greater than or equal to sign, we draw the line normally.

3. to see if the graph passes through the points, we simply plug in the x and y coordinates.
so 2(0)-(3)+3=0. if it's true, which it is in this case, it passes through the points.

4.A (2,0), B (8,5) and C (4,0) we first ploit these points on a graph, connect the dotes to find the lenth of the side of the triangel.
then use pythagrase to find out the lenth, then add them. (too lazy to find the answer for you, but will post if requested.

5. y=x2-2x-8.
i persume x2 means x^2. we first will need to complete the square (i doubt you know what this is so i will show you). to complete the square for a quadratic equation, we find put brackets infront of the first 2 terms.

ex. y=(x^2-2x)-8.

then we factor out any multiplier infront of the variable with a power. since this function has none, we do not need to factor. if it does, for example y=(2x^2+4)-8, we factor it out. it turns in to y=2(x^2+2)-8.

now, we take the multiplier infront of the second variable that does not have power and divided it by 2 and square the answer. so (2/2)^2. that gives 1. note that the 2 is from 2x. not the 2 from x^2. we add and subtract the answer inside the brackets.

ex. y=(x^2-2x+1-1)-8. now, we need to take out the -1. if you previous factored out a number from the x with a power, you need to multiply it to the number you are taking out. so, going back to the previous example where there is a an multiplier (y=2(x^2+2)-8) => (y=2(x^2+1-1)-8) ), we have something like this: y=2(x^2+1)-2-8.

anyways, going back to the function you posted. its now y=(x^2-2x+1)-1-8. then we do math. y=(x^2-2x+1)-9. then we factor the brackets.

so (x^2-2x+1) => (x-1)^2. (i hope know how i got that).

now the function is in the form of y=(x-1)^2 -9. always note that the x coordinate of the vertex is the opposite of the number that's acting upon x. since it's a -1, the x coordinate is 1. y coordinateis the same, so -9. vertex is (1,-9). to find the intercept, just plug in 0. y=0 means x intercept, x=0 means y intercept.

axis of symmetry is mearely the x coordinate of the vertex.

note that if theres negative sign infront of x, by that i mean (-x) not -(x), the parabola open's downwards. positive means upward.

i hope you enjoyed your read, pm for more help.

[BrbGettinHyooge]

EDIT: Got it.

[EthNick]

pretty boss thread

[NitroStigs]

Alright chemistry lovers, I need some serious help here. If anyone has the chemistry zumdahl eighth edition book, go to chapter 13 section 3, and I need help with problems 54, 56, and 58. But if you don't, I will write up the questions below.

54)
At 25 degrees C, K=0.090 for the reaction h2o(g)+Cl2O(g)<->2HOCl(g)

Calculate the concentrations of all species at equilibrium for each of the following cases.
A) 1.0 g h2o and 2.0 g Cl2O are mixed in a 1.0-L flask

B) 1.0 mol pure HOCl is placed in a 2.0L flask.

56)
At a particular temperature, Kp = .25 for the reaction N2O4(g)<->2NO2(g)

A) a flask containing only N2O4 at an initial pressure of 4.5 ATM is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases.

B) a flask containing only NO2 at an initial pressure pressure of 9.0 ATM is allowed to reach equilibrium. Calculate the equilibrium partial pressures of gases.

C) from your answers to parts a and b, does it matter from which direction an equilibrium position is reached?

58)
At a particular temperature, k=4.0times10^-7 for the reaction

N2O4(g)<->2NO2(g)

In an experiment, 1.0 mol N2O4 is placed in a 10.0l vessel. calculate the concentrations of N2O4 and NO2 when this reaction reaches equilibrium.

PLEASE HELP lol

[AsianAesthetics]

Alright chemistry lovers, I need some serious help here. If anyone has the chemistry zumdahl eighth edition book, go to chapter 13 section 3, and I need help with problems 54, 56, and 58. But if you don't, I will write up the questions below.

54)
At 25 degrees C, K=0.090 for the reaction h2o(g)+Cl2O(g)<->2HOCl(g)

Calculate the concentrations of all species at equilibrium for each of the following cases.
A) 1.0 g h2o and 2.0 g Cl2O are mixed in a 1.0-L flask

B) 1.0 mol pure HOCl is placed in a 2.0L flask.

56)
At a particular temperature, Kp = .25 for the reaction N2O4(g)<->2NO2(g)

A) a flask containing only N2O4 at an initial pressure of 4.5 ATM is allowed to reach equilibrium. Calculate the equilibrium partial pressures of the gases.

B) a flask containing only NO2 at an initial pressure pressure of 9.0 ATM is allowed to reach equilibrium. Calculate the equilibrium partial pressures of gases.

C) from your answers to parts a and b, does it matter from which direction an equilibrium position is reached?

58)
At a particular temperature, k=4.0times10^-7 for the reaction

N2O4(g)<->2NO2(g)

In an experiment, 1.0 mol N2O4 is placed in a 10.0l vessel. calculate the concentrations of N2O4 and NO2 when this reaction reaches equilibrium.

PLEASE HELP lol

54)
are you sure h2o is a gas and not a liquid? if it's a gas then idk the answer.
56) sorry idk how to do ATM
58)
first, we turn the given chemicals to it's molarity.
1.0mol/10.0L= 0.10M (2 sigfigs)
then we write out the equilibrium constant equation
N2O4(g)<->2NO2(g)
4.0x10^-7=[NO2]^2/[N2O4]

then we do a ICE table

N2O4 = 2NO2
I 0.10 0

C -x 2x (note we use ratio in change)

E 0.10-x 2x

now we plug it in the equation.

4.0x10^-7=[NO2]^2/[N2O4]
4.0x10^-7=[2x]^2/[0.10-x]
=>
4.0x10^-7=(4)(x^2)/[0.10-x]
after isolating x, do 0.10-x and 2x and you get the concentration at equilibrium.

this is the same method for question 54, although i think h2o is a liquid in the equation because if it's a gas, then you don't get an answer.

[NitroStigs]

Ya it's gas, sorry my bad man. And thanks for the help, greatly appreciated! I've already converted grams to mols for 54 A

And for 56, ATM is atmospheres

[AsianAesthetics]

Ya it's gas, sorry my bad man. And thanks for the help, greatly appreciated! I've already converted grams to mols for 54 A

And for 56, ATM is atmospheres

oh sorry i screwed up during my work for 54. i just don't know how to do 56.
we'll start off with writing the equation for the reaction's equlibrium constant:
h2o(g)+Cl2O(g)<->2HOCl(g)
[HOCl]^2/[h2o][Cl2O]=0.90

a) since we're giving grams of the reactants, we need to covert it to mols to find out it's molarity. h2o: 1 / (2+16)= 0.056 mol. divde that by 1 gives 0.056M. note that it's 2 sig figs.

Cl2O: 2/(35.5+16) = 0.039 mol => 0.039M.

now, we'll need a ICE table to figure out what will happen.
h2o + Cl2O = 2HOCl
I 0.056 0.039 0

C -x -x 2x (use the ratio during change stage.

E 0.056-x 0.039-x 2x

then we plug this in the equation we've estableshed.

[HOCl]^2/[h2o][Cl2O]=0.90
[2x]^2/[0.056-x][0.039-x]=0.90
take the square root of top and bot
(4)(x)^2/[0.056-x][0.039-x]=0.90
after for isolating x, plug in x for the E column and you can find out it's concentration at equilibrium.

for B, just do exactly what happened above except your just going backwards.

[aggieman122]

Anybody know how to do titration problems in chemistry?

I have 3 but here's one of them. I'm hoping to learn how to do it so i can do the other two by myself. Thanks for the help!

Determine the volume of .020 M HCl solution needed to neutralize 20.0 mL of 0.56 M NaOH