Friday

January 20, 2017
Total # Posts: 1,968

**Biology Chemistry Part**

I'm trying to calculated the rate of reaction In this lab I took a 50 mL beaker and poured in 10 ml of cold distilled water into it, I then poured in 30 ml of original enzyme solution (I believed we used cold potato juice or something), I then took a piece of paper and ...

*September 26, 2010*

**Biology Chemistry Part**

I'm trying to calculated the rate of reaction In this lab I took a 50 mL beaker and poured in 10 ml of cold distilled water into it, I then poured in 30 ml of original enzyme solution (I believed we used cold potato juice or something), I then took a piece of paper and ...

*September 26, 2010*

**algebra**

thank you

*September 25, 2010*

**algebra**

3x+y=7 for y -x+y=13 for y f=5gh for h

*September 25, 2010*

**science**

choose a metal you know and list three uses that illustrate three properties of metals

*September 23, 2010*

**algebra**

solve the equation and check -(9x-4)-(2x-6)+7=-8(x-9)-(6x+2)+4

*September 18, 2010*

**calculus**

Use the following function values to calculate H '(1). f (1) f '(1) g(1) g'(1) 3 -4 8 -1 H(x) = x/(g(x) f(x)) How would this problem be done... i found H(x) to be 1/24 but don't know how to find the derivative of h'(1)

*September 18, 2010*

**algebra**

solve each equation 4(n+3)=2(6+2n)

*September 18, 2010*

**math**

Simplify the expression 4(3z^3-6)+12(2-z^3)=

*September 15, 2010*

**algebra II**

sorry for calling it an equation i mean i have to simplify the expression

*September 9, 2010*

**algebra II**

need help solving the equation 5y-14+7y-20y

*September 9, 2010*

**Math**

Kim is twice the age of Ryan. In 4 years Kim will be 7 years older than Ryan. How old is Kim now?

*September 9, 2010*

**chemistry**

What is the correct formula for calcium nitrate

*September 8, 2010*

**chemistry**

793.4 g

*September 8, 2010*

**chemistry**

a brain weighing 1.0 Ib occupies a volume of 620 ml. What is the specific gravity of the brain?

*September 7, 2010*

**Algebra**

A moving Company weighs 20 boxes you have packed that contain either books or clothes and says the total weight is 404 pounds. You know that a box of books weighs 40 pounds and a box of clothes weighs 7 pounds. Find how many boxes of books and how many boxes of clothes you ...

*September 7, 2010*

**Chemistry**

An alpha particle (mass = 6.6 10-24 g) emitted by radium travels at 2.5 107 ± 0.1 107 mi/h. (a) What is its de Broglie wavelength (in meters)? (b) What is the uncertainty in its position?

*September 5, 2010*

**algebra 1**

how to simplify and solve 2/5(20x+5)-1/2(8-4x)=38

*September 5, 2010*

**math**

Sam ran between 8 and 15 miles a week for 5 weeks.About how many miles could he have run?

*September 1, 2010*

**ALL OF JISHKA STAFF**

Hello I had a couple of questions and was woundering if you have staff members that are teaching or have taught AP BIOLOGY AP PHYSICS B AP CALCULUS AB AP CHEMISTRY I was told that the AP BIOLOGY teacher had gotten extremly ill =(, has he come back? Also can you tell me if you ...

*August 19, 2010*

**English (Biology Essay)**

I know my english is crap any corrections suggestions cirtisims etc. would greatly be apreciated... if you know any biology and find anything that is biologically wrong that would be great as well but don't worry if you don't THANK YOU!!! im putting my initals just in ...

*August 16, 2010*

**Physics**

Convert 5:25:25 to seconds.

*August 16, 2010*

**Algebra**

Available evidence suggests that about 20 percent of the asteroid’s mass turned to dust and spread uniformly over Earth after eventually settling out of the upper atmosphere. This dust amounted to about 0.02 g/cm^2 of Earth’s surface. The asteroid very likely had a ...

*August 16, 2010*

**Calculus**

dont worry about it i think i'm gettin g some where

*August 12, 2010*

**Calculus**

actually cos(x)=-2 has an infinte amount of solutions so to say it dosen't have ONE is just wrong... but yah I don't buy that the equation, in some post below doesn't have critical points they are defined I found them, but whatever anyways can you help me simplify ...

*August 12, 2010*

**Calculus**

same as my question below please help me post your answer on here if you have one on these forms of course h t t p : / / w w w . p h y s i c s f o r u m s . c o m / s h o w t h r e a d . p h p ? t = 4 2 1 7 6 3

*August 12, 2010*

**Calculus**

no one on physics forums seems to know the answer so I was wondering if you guys could help post anser on these forms of course if you can help my question is here h t t p : / / w w w . p h y s i c s f o r u m s . c o m / s h o w t h r e a d . p h p ? t = 4 2 1 7 5 8

*August 12, 2010*

**Chemistry**

For many years the recovery of gold-that is, the seperation of gold from other materials-involved the use of potassium cyanide: 4AU + 8KCN + 02 +2H20 -> 4KAu(CN)2 + 4KOH What is the minimum amount of KCN in moles needed to extract 29.0 g (about an ounce) of gold? Now my ...

*August 2, 2010*

**physics**

And it's around 16.4 -- I just can't get it to the exact value that the Webassign will accept. Thank you again!

*July 28, 2010*

**physics**

They are connected by a string -- unfortunately I am unable to link the diagram. I believe that for the purpose of the problem they are ideal strings.

*July 28, 2010*

**physics**

In the figure we see two blocks connected by a string and tied to a wall, with theta = 33°. The mass of the lower block is m = 1.0 kg; the mass of the upper block is 2.0 kg. The tension of the string connecting the blocks is 5.337. Find the tension in the string that is ...

*July 28, 2010*

**Algebra I**

Rectangle ABCD has vertices C and d on the x-axis and vertices A and B on part of the parabola y = 9 - x^2 that is above the x-axis. a.) Find the coordinates of A, B, C, and D in terms of x. b.) Determine the Area of the rectangle as a function of x. c.) What is the domain for...

*July 28, 2010*

**Math**

x +/- 3 is that mroe simplified then writing it out x + 3, x - 3 I thought it would be becaue we normally say simple is when all of the operations that could be done is done in which case the second choice is more simple? I'm just woundering because i'm doing a summer ...

*July 28, 2010*

**Calc**

I'm trying to write an equation for all the infinite values of the equation -i ln(2 + sqrt(3) ) people have told me that its pi(2n + 1) -i ln(2 + sqrt(3) ) I don't see how so I plug in numbers for n and don't get the same answer usign my calculator please explain ...

*July 27, 2010*

**CALC**

1. The problem statement, all variables and given/known data cos(x) = -2 I was trying to solve that problem ignoring what people say about it not being defined and got a number strangely. I showed step by step so you can tell me what I did wrong as I don't think I did ...

*July 27, 2010*

**Calc**

1. The problem statement, all variables and given/known data cos(x) = -2 I was trying to solve that problem ignoring what people say about it not being defined and got a number strangely. I showed step by step so you can tell me what I did wrong as I don't think I did ...

*July 27, 2010*

**Algebra**

Having some trouble graphing this y = 3 - x for x less then or equal to 1 y = 2x for x greater than one how do I indicate that for the first part (1, 2) there would be a closed point at that cordinate but for the second part an open point at those same exact cordinates how do ...

*July 27, 2010*

**Algebra**

(60 + 16sqrt(15))/(60 + 17sqrt(15)) i tried dividing but got stuck thanks

*July 26, 2010*

**Calculus**

Find the range of y = (3x-1)/(2x^2 + x - 6) I was going to take the derivative of the numerator and denomenator and then use the quotent rule to find the derivative of the function and find the critical values but I ran into the imaginary number during the proess and am ...

*July 25, 2010*

**Calc I**

Find the range of y = (3x-1)/(2x^2 + x - 6) I was going to take the derivative of the numerator and denomenator and then use the quotent rule to find the derivative of the function and find the critical values but I ran into the imaginary number during the proess and am ...

*July 25, 2010*

**Math (Very Easy Math)**

I'm kind of confused as to what simplified mean? Can you please provide me with a definiton... Like I'm kind of stumped as to what one is more simplified -7(2x + 3) or -14x -21 Please explain what it mean for an expression to be "simplified"

*July 24, 2010*

**Calc I**

Solved

*July 24, 2010*

**Calc I**

Yes I was trying to find the range y = (x^2 -4)/(x^2 - x -12) ok using 2(4 +/- sqrt(15) ) sorry I forgot the minus in the derivitive but ya that makes sense but however I need three critical values that only gives me graph it and you'll see there are three how do I find ...

*July 24, 2010*

**Calc I**

y = (x^2 -4)/(x^2 - x -12) dy/dx of numerator I got 2x dy/dx of denomenator I got 2x - 1 dy/dx of y I got (x^2 - 16x -4)/((x-4)^2(x+3)^2) setting numerator to zero and solving got 8 +/- sqrt(65) with the critical value being the + setting denomenator to zero and solving got 4 ...

*July 24, 2010*

**Algebra I**

I'm stuck on this problem please help me find the range of this equation y = (x^2 - 4)/(x^2 - x - 12) I know that it is [1/3,-infintiy]U[?,infinity] yes I'm having trouble with that ? At first I was like ok there should be a horizontal asymptote at y=1 there is in ...

*July 23, 2010*

**Algebra I**

Ok so I kind of forgot how to do this so I looked up on the internet and was told divide the coefficent in the numerator of the highest degree by the highest coeficent of the highest degree in the numerator and that should be your horizontal asymptote one problem f(x) = (x^2 -...

*July 23, 2010*

**Algebra I**

nevermind

*July 23, 2010*

**BobPursley**

h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 7 9 9 0 5 6 1 4 well it's on this page just CTRL+F Kate you can post here if you want thanks!

*July 23, 2010*

**algebra**

Use the quadratic formula (40 +/- sqrt((-40)^2 - 4(-6)(-50) ))/(2(-6)) what ever that comes out to be

*July 23, 2010*

**Trig**

I thought that this was already in radians by the way... ln( (4i +3)/5)/i why is it not considered to be in radians?

*July 23, 2010*

**RESPONSE**

My instructions were just to "Evaluate" why is that not considered an angle?

*July 23, 2010*

**Trig**

I was doing this problem sin^-1 (4/5) if I'm not mistaking most teachers would say that .927295218 radians is wrong is just an estimation and therefore is wrong so I'm justified in putting this on my paper instead right ( ln( (4i +3)/5)/i ) right? She couldn't mark...

*July 23, 2010*

**Trig**

Even if you have no idea what on earth any of this stuff is but have a vast knowledge in complex number system you might be able to help me as this is what I believe is preventing me from making sense of this stuff... Ok I'm trying to understand how you would know that sin...

*July 22, 2010*

**Algebra I**

Did I do these probelms correctly? Find the intercepts 1. y^2 = x^2 - 4x y^2 = x(x - 4) Y intercepts y^2 = 0(0 - 4) (0,0) x intercepts 0 = x(x - 4) 0 = x - 4 4 = x (4,0) 2. y = (x (x + 3))/(3x + 1)^2 y intercetps y = (0(0 + 3))/(3(0) +1)^2 y = 3/1 (0,3) x intercepts 0 = (x (x...

*July 21, 2010*

**Algebra**

see like I'm kind of confused by this as well isn't this more simple x^-1 rather than 1/x ? can you please give like a deffinition of "simple" for equations what does it mean for an equation to be in it's most simplest forms? That I can apply to any ...

*July 21, 2010*

**Algebra**

Which one is more "simple"? (-7(2x + 3))/(x(x + 3)) or (-14 x + 21)/(x^2 + 3x) I would go with the factored form but i'm still kind of confused as to what exactly what it means for an equation to be "simple"

*July 21, 2010*

**Algebra**

I'm kind of confused as to what exactly simplified means by deffintion which one is more simple (2x)^6 or 64x^6 I thought simplified meant to do all the operation that can be done... but I've had some teachers who've makred that wrong because I didn't factor...

*July 21, 2010*

**Algebra**

What does it mean to be "simplified" which one is most "simple" 2(3+5) or 6 + 10 ??? I've been told both and wonder if someone can give me the correct answer some of my teachers told me simplified means all of the operations that can be done are done ...

*July 21, 2010*

**NEVERMIND**

figuered it out

*July 20, 2010*

**Algebra II**

ok now this is an algebra 2 problem... I have goten far down to hear e^(ix) = (4i +/- 3)/5 now how do I solve for x I feel really stupid now as this is algebra 2... can't use natural log right or the common log as ln( e^(ix) ) does not equal ix so what do I do?

*July 20, 2010*

**Calc**

ok this is now an algebra question...

*July 20, 2010*

**Calc**

how do I solve this arcsin(4/5) note that I am not looking for about 53 degrees I believe I'm suppose to solve euler's formula for x i.e. sin (x) = (e^(ix) - e^(-ix))/(2i) where x is in radians hence I would do something like this sin (x) = (e^(ix) - e^(-ix))/(2i) = 4/...

*July 20, 2010*

**Algebra 2**

how do I find the length and width of a rectangle when the width of the rectangle is 3 feet less tahn the length. The area is 18ft^2

*July 17, 2010*

**Jishka Staff**

Oh is there another one or are there no more on here who teach biology besides that teacher?

*July 13, 2010*

**Jishka Staff**

Is you teacher who teaches AP Biology still sick last time I heard I was told he was to sick to even come on here is he back yet... i also am unsure of his name... thanks

*July 13, 2010*

**college**

let i = the square root of -1 with i to the 1st power =i, i to the 2nd power= -1, i to the 3rd power =-i , i to the 4th power=1 find ito the power 215

*July 5, 2010*

**Biology/Math person please help**

Will thanks for the help and ya native language is actually English... I just have a hard time making sense of what the college board is trying to say sometimes that is all lol... but ya can somebody who knows biology well and a little bit of math check this out please thanks...

*July 4, 2010*

**Sorry**

didn't know see your posts let me read them ignore these posts for the moment sorry :(

*July 4, 2010*

**Biology (To SraJMcGin or anyone who can help)**

Well I have found bits and pieces of that test online and found part of those questions on some power point that had 1986 next to it and the number of the question but no answers though...

*July 4, 2010*

**Biology (To SraJMcGin or anyone who can help)**

Ok can't right click copy paste scroll to the very top and you should be able to see the link and copy it into the adress bar with no spaces then press enter... The reason why I did that becasue the question was a couple of pages back and I cant post links If its easier ...

*July 4, 2010*

**Biology (To SraJMcGin or anyone who can help)**

h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 7 8 2 7 9 5 7 9 It's a webadress cant post links put it in your adress bar and delete the spaces then press enter. Thanks for the responses! By the way believe it or not those are actually from ...

*July 4, 2010*

**Biology (Please Dont Skip Over)**

h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 7 8 2 7 9 5 7 9

*July 4, 2010*

**Biology**

I think my questions were skipped over ignore this post if this is not so... h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 7 8 2 7 0 5 2 8 h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 7 8 2 6 9 0 4 4 please post ...

*July 4, 2010*

**Biology**

Questions 109-111 refer to the map below of the distribution of several populations on the continents of Eurasia and North America. These populations were derived from a common ancestral species. The area enclosed by a given dotted line represents the distribution of the ...

*July 4, 2010*

**Biology**

Iwas woudnering if you could help me with this problem. The answer key says that the answer is D and I have no idea why. The chart, included in the link, reads off a value of about .5 for the G locus for the year 1980 Finding the percent heterozygous should be as sipmle as 2(....

*July 4, 2010*

**Chemistry**

Ok apparently its just the mole ratio 2:1 from the coefficents so I just do 2(.507) to get my answer but how come I ignoered the coeficent of the Si in ther reaction?

*July 3, 2010*

**Chemistry**

Thanks for the help earlier My question Silicon tetrachloride (SiCl4) can be prepared by heating Si in chlorine gas: Si + 2Cl2 yields SiCl4 In one reaction 0.507 mole of SiCl4 is produced. How many moles of molecular chlorine were used in the reaction? Ok is it makeing ...

*July 3, 2010*

**Chemistry**

I know mathematically I can write chemical reactions this way but in chemistry can I if now why? 2K + 2(H20) yields 2KOH + H2 2(K + H20) yields 2KOH + H2 can I also do this if not why? 2(CO) + O2 yields 2(CO2) O(2C + O) Yields 2(CO2) I don't see why I cant do any of these ...

*July 3, 2010*

**Chemistry**

I have realized I don't understand Avagado's number at all My book shows me this diagram instead of just providing a simple formulas that makes no sense at all here is what I have made sense of so far (6.022 x 10^23 atoms/mol)(mass of element) = molecular mass were ...

*July 3, 2010*

**Chemistry**

What is wrong with or ambiguous about the phrase "four molecules of NaCl" I really don't understand my textbook says in the back that it is an ionic compound so I guess that its not really a molecule then I don't understand...

*July 2, 2010*

**AP Biology**

I got a question that comes from the 1990 released test #61 that I'm completley lost on 61. In a population that is in Hardy-Weinberg equilibrium, the frequency of a recessive allele for a certain hereditary trait is 0.20. What percentage of the individuals in the next ...

*July 2, 2010*

**Public High School AP Biology**

I got a question that comes from the 1990 released test #61 that I'm completley lost on 61. In a population that is in Hardy-Weinberg equilibrium, the frequency of a recessive allele for a certain hereditary trait is 0.20. What percentage of the individuals in the next ...

*July 1, 2010*

**physics**

danks 4 includN units kid refuse to solve w/o dem sorry

*July 1, 2010*

**Chemistry (algebra I problem)**

I feel really dumb because I cant figuer out this simple algebra I problem... 84. The diameter of a copper (Cu) atom is roughly 1.3 x 10^-12 m. How mnay times can you divide devenly a piece of 10-cm copper wire until it is reduced to two separate copper atoms? (Assume there ...

*June 28, 2010*

**Public High School AP Biology**

I got a question that comes from the 1990 released test #61 that I'm completley lost on 61. In a population that is in Hardy-Weinberg equilibrium, the frequency of a recessive allele for a certain hereditary trait is 0.20. What percentage of the individuals in the next ...

*June 22, 2010*

**Chemistry**

What is the pH of a 0.42 M NH4NO3 aqueous solution? What is the percent ionization?

*June 20, 2010*

**Chemestry**

What is the pH? 1.6 x 10^(-5)?

*June 19, 2010*

**Algebra**

Thanks!

*June 18, 2010*

**Algebra**

Is this correct? If not can you please tell me what steps I did wrong? Thanks! The hydrogen ion concentration of milk is about 1.6 x 10^-7 moles per liter. Find the pH. pH = -log [H+] pH = -log[1.6 x 10^-7] pH = -(-7.204119983) pH = 7.2 The pH balance of the milk is 7.2

*June 18, 2010*

**Calc**

I'm kind of rusty on my calc here... ok ther's a graph of velocity vs time w/ velocity in m/s and time in seconds were time is of course the x-axis k I'm asked to describe how the velocity changes over the timer interval in this interval the graph consists of three...

*June 17, 2010*

**Algebra**

It is actually for an Intermediate Algebra class. Logitharims.

*June 17, 2010*

**Algebra**

The hydrogen ion concentration of milk is about 1.6*10^-7 moles per liter. Find the pH.

*June 17, 2010*

**Calculus**

How to prove this (e^(2^-1 i3pi) - e^-(2^-1 i3pi))/(2i) = -1 if you could show me this that would be really great btw e is eulers number i = imaginary number sqrt -1 and pi = 3.14... THANKS!!!

*June 11, 2010*

**Algebra 2**

a rectangle table is five times as long as it is wide if the area is 245 feet ^2 find the length and width of the table

*June 7, 2010*

**chemistry**

How much Fe++ could be present in water containing 0.8 x 1e-02 M HCO3- (bicarbonate) without causing the precipitation of FeCO3 (Ksp=10**(-10.7))

*June 4, 2010*

**Chemistry**

nevermind..i got it

*May 26, 2010*

**Chemistry**

Magnesium fluoride dissolves in water to the extent of 8.0 10-2 g/L at 25°C. Calculate the solubility of MgF2(s) in moles per liter, and calculate Ksp for MgF2 at 25°C. I've been doing this and getting .086. Please help!

*May 26, 2010*

**Algebra**

Write an equation of the line satisfyingg the given conditions. Slope = -2/3; y-intercept of 2

*May 23, 2010*

**Math (trig)**

4cos(x)+5=6sec(x)

*May 20, 2010*

**Algebra**

Determine whether the lines are parallel, perpendicular, or neither. y = 9x + 9 and y = -9x + 9

*May 16, 2010*