Wednesday

February 10, 2016
Total # Posts: 226

**Math**

(3-4sin^2A)(1-3tan^2A) =(3-tan^2A)(4cos^A-3)
*October 14, 2015*

**Maths **

theo invests £800 in an account that pays 2% simple interest each year how much interest is earned in a year how much there will be in the account after 5 years how much will there be in 10 years
*May 17, 2015*

**physics**

A river is flowing along the east direction with a velocity of 10km/hr. A person heads towards north with a velocity of 2km/hr. what is the velocity of the person with respect to ground?
*November 30, 2014*

**phy111**

1.5 m
*October 25, 2014*

**chemistry**

What must be the velocity of a beam of electron if they are to display a de broglie wavelength of 1A°?
*July 6, 2014*

**Ms sue please help**

Thanks a lot Writeacher :)
*May 13, 2013*

**Ms sue please help**

Hey ms sue can you please help me to simplify this paragraph? Raynaud's disease occurs when the small arteries (arterioles) that serve the fingers, toes, ears, or nose go into spasm. When arterioles go into spasm, they cut off blood supply and cause digits (fingers and ...
*May 13, 2013*

**Raynaud's**

I want to know what Raynaud's basically is. I know that blood flow is stopped to the fingers and toes, because blood vessels tighten or something when they are exposed to cold, and there are other factors as well.
*May 11, 2013*

**Raynaud's **

Hey I want to shorten this paragraph out which tells what Raynaud's is, can anyone please simplify it and make it shorter thanks? Raynaud's disease occurs when the small arteries (arterioles) that serve the fingers, toes, ears, or nose go into spasm. When arterioles go...
*May 11, 2013*

**Biology Raynaud's Disease**

Hey im doing a powerpoint presentation on this raynaud's disease, and could someone please give me some good sites to go through to get info abt this and please mention anything you know about the raynaud's disease as well, thanks.
*April 30, 2013*

**Biology - URGENT Enzyme Lab**

Did a catalase producing hydrogen peroxide lab, used manganese dioxide, fresh frozen liver, potato, ice, fine clean sand, etc. Basically just added hydrogen peroxide to the catalysts under diff conditions and stuff. Just dont get this question which is : how do you account for...
*April 5, 2013*

**Biology Difference b/w Heat Exhaustion/Heat Stroke**

I want to know the causes of heat stroke and heat exhaustion. I cant seem to find separate causes for the two, finding very different answers online :|
*February 8, 2013*

**Biology**

Hey I am doing a lab, the link is down h t t p : //w w w . sd67 . bc . ca/schools/salc/biology%2012/module%20c%20-%20human%20biology/unit%2010%20-%20respiratory%20system/Homeostasis%20Lab .pdf And I really would like help with #1 My data is right here Pre exercise 0 min - Temp...
*February 7, 2013*

**Chemistry 12**

which of the following 0.10M solutions is basic? A LiCl B K3Po4 C NaCLO4 D NH4NO3 Is it C?
*January 25, 2013*

**Chemistry 12**

Thank you soo much :) I can totally see you as a smart Chemist in the future :)
*January 25, 2013*

**Chemistry 12**

Thank you soo much, that makes so much sense :)
*January 25, 2013*

**Chemistry 12**

define the term strong bronsted lowry acid it is 100% ionized in solution? is that it?
*January 25, 2013*

**Chemistry 12**

name a compound that acts as a weak base? methanol? define the term weak bronsted-lowry base im not sure how to put this in words, but a weak base is found when you got a strong acid, when your ka is high, kb will be low.
*January 25, 2013*

**Pre Calculus 12**

Oh but this is a multiple choice question and the only answers that it can be are A 144 B 72 C 24 D 1728
*January 25, 2013*

**Pre Calculus 12**

permuations an orchestra has 2 violinsts, 2 cellisst, and 4 harpists. Assume that the players of each instrument have to sit together, but they can sit in their own group. In how many ways can the conductor seat the members of the orchestra in a line? I just went 4*3*2 and got...
*January 25, 2013*

**Chemistry 12**

Thanks soo much to both of you :)
*January 25, 2013*

**Chemistry 12**

Thanks so much :) So if we were to find the Ka, then we would use the ka on the acid side of the chart?
*January 25, 2013*

**Chemistry 12**

How do you know which ka to use? There is one on the base side of the chart, and one of the acid side of the chart. For the one of the acid side of the chart, the Ka is 2.2*10^-13 And for the one on the base side of the chart, it is 6.2*10^-8.
*January 25, 2013*

**Chemistry 12**

The value of Kb for HPO₄²- is? A. 2.2*10^-13 B. 6.2*10^-8 C. 1.6*10^-7 D. 4.5*10^-2 I dont get how to solve this.
*January 25, 2013*

**Chemistry 12**

Aww thanks soo much buddy :)
*January 25, 2013*

**Chemistry 12**

The [OH-] of a solution with a PH 5.75 is is it 5.6*10-9M?
*January 25, 2013*

**Pre Calculus 12**

Oh that makes sense, thank you :)
*January 24, 2013*

**Pre Calculus 12**

Identify the point on the unite circle coressponding to an angle of 300 degrees in standard position A (-√3, -√3/2) B (-√3/2, 1/2) C (1/2, -√3/2) D (1/2, -√3 ) I dont get how to figure this out :|
*January 24, 2013*

**Pre Calculus 12**

Another sine/cosine question i dont get in vancouver on certain day, high tide is 20m at 2am, the next low tide is 8m at 6am, what an equation that represents height (h)of water at any time (t)since midnight) what is the height of water at 8:45AM? What is height of water at 8:...
*January 23, 2013*

**Pre Calculus 12**

Modelling with sine/cosine A Ferris wheel has a diameter of 30m. The bottom of the wheel is 1.5m off the ground it takes 3.5min to make one complete revolution. a person gets on ferris wheel at its lowest point at time = 0. write an equation that represents persons height ...
*January 23, 2013*

**Pre Calculus 12**

The height h, in metres, above the ground of a car as a ferris wheel rotates can be modelled by the function h(t) = 18cos(πt/80) +19 what is the minimum height of a car? do i like subtract 19 from 18 ? what is the maximum height of a car? do i add the 19 to 18? how long ...
*January 23, 2013*

**Pre Calculus 12**

so you added 10 and 2 to get 12, and amplitude is the middle of max and min? how did you get the axis 4 units? a period is always twice of something? the phase shift is sort of confusing me, because isnt that just between the x values? 2, and 5? is there some other way to ...
*January 23, 2013*

**Pre Calculus 12**

Graphing trigonometric functions A sinusoidal function has a maximum at (2,10) and its next minimum (5,-2) find an equation that represents this situation A sinuosoidal function has a zero at (5,0) and its next minimum is (7,-4). find an equation that represents this situation...
*January 23, 2013*

**Pre Calculus 12**

Thanks very much Reiny :)
*January 23, 2013*

**Pre Calculus 12**

Laws of logarithms evualuat using change of base rule log(√8)16 ^the square root 8 is supposed to be subscript. the answer i got was 8/3, not sure if that is right
*January 23, 2013*

**Pre Calculus 12**

thanks soo much Reiny :) You are such a great math helper on here! :D
*January 23, 2013*

**Pre Calculus 12**

how do i log both sides? divide by 2000 on both sides?
*January 23, 2013*

**Pre Calculus 12**

Solving problems that involve logarithms the sound at a rock concert decreases by 10% for every 5m travvelled. how far does it take for a volume of 2000 decibels to decrease to 20 decibels? i dont know what to do for this one the growth decay formula i got is A = P(X)^t/n I ...
*January 23, 2013*

**Pre Calculus 12**

Thanks very much Reiny :)
*January 23, 2013*

**Pre Calculus 12**

Laws of Logarithms Evaluate: without using a calculator, except for the first one. The 5.6 is supposed to be subscript, but i dont know how to make it small. 4log(5.6)84 log84/log5.6 Do I multiply this by four or something? both of the logs?
*January 23, 2013*

**Pre Calculus 12**

How is 5y-3 is a common denominator?
*January 22, 2013*

**Pre Calculus 12**

Could you explain why it wouldnt be 1/5x again? Because isnt there an invisible 1 beside the x, and so when we divide the 5 doesnt it become 1/5x? For the second equation to get rid of 5y-3 on the bottom you multiply it on the other side? Could you explain step by step the ...
*January 22, 2013*

**Pre Calculus 12**

Oh okay that makes sense, Im just sort of still confused with how the answer to the first one needs to be layed out I got y = ³√(1/5x) +3 And yes that is a new equation on my second post, and yeah I meant that, sorry will remember to put brackets next time.
*January 22, 2013*

**Pre Calculus 12**

And I do not get this one y = x-2/5x-3 x = y-2/5y-3 ?
*January 22, 2013*

**Pre Calculus 12**

Where did you get 4 from? For the first one? Where you wrote in original let x = 4?
*January 22, 2013*

**Pre Calculus 12**

I also do not get these inverses questions y = 5(x-3)^3 x = 5(y-33)^3 I divided 5 on both sides and got 1/5x = (y-3)^3 Then do I cube root the 1/5x or something to get rid of of the cubed on (y-3)? Also y = x-2/5x-3
*January 22, 2013*

**Pre Calculus 12**

Thanks Reiny that makes soo much more sense :)
*January 22, 2013*

**Pre Calculus 12**

For the second step, to get rid of a fraction on the bottom, we always multiply it with every term? And if we are dividing something, then we divide it by every term? K i get how you got 6, but I still dont get how to get the x+4 ?
*January 22, 2013*

**Pre Calculus 12**

thanks Reiny but the answer says y=3/2(x+4) is it supposed to be 6?
*January 22, 2013*

**Pre Calculus 12**

Im trying to find the inverse of this: y = 2/3x-4 I got to this step x+4 = 2/3y I need to divide by 2/3 to get rid of 2/3 beside the y, but i dont know how to divide x+4/2/3 that looks complicated :\
*January 22, 2013*

**Pre Calculus 12**

Im going over my pre calculus 12 exam, and I need help with one question from the chapter Transformations of graphs and stuff. Combining Transformations 2y = f(5x-10)+8 The original points are (4,6) and the new points I got by translating it and stuff are : (14/5,20) But in ...
*January 22, 2013*

**maths**

U+2085
*January 19, 2013*

**Pre Calculus 12 urgent**

andrew is working on a binomial problem (1/2x-y)^7. He asks u to : i) what the coefficient of the 6th term ii) find the term that has the variabes x^47^3 (ex. 34x^4y^3) iii) find the first three terms of the expansion I really need help with that ^ . I know the powers of A ...
*January 18, 2013*

**Pre Calculus 12**

Im on the chapter of permutations/combinations/fundamental counting principle need help with 2 questions 1. emma is arranging her books in piles on her desk. she has 5 math books, 3 english books, and 4 science books. how many ways can she arrange them if she wants to keep the...
*January 18, 2013*

**Pre-Calculus**

Same problem with this question The angle θ is in the fourth quadrant, and tan θ = -3/7. Point P is on the terminal arm of angle θ. Which is a possible coordinate for P? A) -21,9 B) 9,-21 C) -9,21 D) 21,-9
*November 14, 2012*

**Pre-Calculus**

The angle θ is in the second quadrant and tan θ = -3/5. Point P is on the terminal arm of angle θ/ Which is a possible coordinate for P? A) (-5,√29) B) (-3,√29) C) (-10,6) D) (-6,10) I drew the triangle, and aren't the coordinates supposed to be...
*November 14, 2012*

**Pre-Calculus**

Thanks so much :)
*November 6, 2012*

**Pre-Calculus**

Trigonometric Functions, Radian Measure ∏ <-- will be using this for pi Using exact values, convert to radians ( hint use fraction of ∏) 90° = 90°*∏/180° = 1∏/2 ^^would it be right to also call it 2∏ radians? Determine the angle at ...
*November 6, 2012*

**Pre-Calculus**

Applications of Logarithms I really need help with this log stuff please. If the PH of acetic acid is 5, what is the PH of hydrochloric acid if it is 200 times more acidic? the formula is right here: P=P0*10^PH2-PH1 200=10^5-PH1 log200=(5-PH1)log10 And I dont know where to go ...
*October 20, 2012*

**Pre-Calculus - Reiny**

Reiny you helped me with this logarithm yesterday: How did you write it out as log2 ( √A / B^3 ) Laws of logarithms combine, write as a single logarithm Need help on this question please, Im stuck, dont know where to go abouts from here: I did it on paint and uploaded it...
*October 17, 2012*

**Pre-Calculus**

Laws of logarithms combine, write as a single logarithm Need help on this question please, Im stuck, dont know where to go abouts from here: I did it on paint and uploaded it onto this website because I dont know how to do the subscript numbers, so it probably wouldnt really ...
*October 16, 2012*

**Pre-Calculus**

Laws of Logarithms Without using a calculator use the change of base rule to evaluate 1. a) log(subscript8)32(hint use base 2) =log(subscript2 32)/log(subscript2 8) = 5/3 b) log(subscript36)1296. This one doesnt even give you a hint, so how do you know which base to use? Does ...
*October 16, 2012*

**Pre-Calculus**

Oh so they always have to be in hours? growth periods are always in hours?
*October 16, 2012*

**Pre-Calculus**

Exponential Functions A=P(X)^t/n A-final amount P-initial amount X-growth rate t-time n-number of growth periods The teacher had this question as an example and did it however i do not understand one thing: The Ebola virus double every 30 min. If there are currently 2000 ebola...
*October 16, 2012*

**Pre-Calculus**

Exponential Functions This is my equation that models the accumulated amount (A) at any time t. A = 1000(1+0.08/12)^t*12 ^ How do I plot that into the graphing texas instruments calculator? What I do I type in the y-axis?
*October 8, 2012*

**Pre-Calculus**

solve by fully factoring x^3-7x-6=0 How would I fully factor this?
*October 2, 2012*

**Pre-Calculus**

Radical Functions Graph y=(x-3)(x+2) and y=√(x-3)(x+2). where are the x-intercepts of each function ?why? for the first one, i know that whatever is inside the brackets is opposite, so the x intercepts would be at 3, and -2. but the whole radical thing is it the same ...
*October 2, 2012*

**Pre-Calculus**

for the last two you did how do you know the x is becoming large like that whole infinity thing?
*October 2, 2012*

**Pre-Calculus**

sorry that was the wrong question I meant the degrees of these one were both the same: y = x^2+5x-6/x-3x^2+9 the leading coefficient is 1, so the vertical asymptote would be one?
*October 2, 2012*

**Pre-Calculus**

Rational Functions y = (x^2+7x-4)/(x-2) Since the degrees of both the numerator and denominator are the same, I would use the leading coefficient, and both the rational functions start with 1, so would the horizontal asymptote be 1? Also dont get how to find the horizontal ...
*October 2, 2012*

**Pre-Calculus**

Rational Functions does the following function have a hole or a vertical asymptote or both? how do you know? find the y-value at that point. y=x^2+7x+12/x^2+8x+15 I factored this out to y = (x+3)(x+4)/(x+5)(x+3) The x+3's cancelled out. I dont get the whole verticle and ...
*October 2, 2012*

**Chemistry**

Alright but since heat is released wouldn't it be negative? the H notation?
*September 30, 2012*

**Chemistry**

I'm having a hard time understanding Endothermic and Exothermic reactions, like their standard format and stuff. For Exothermic reactions the heat is getting released into the surroundings, the products will be less than the reactants, so I would assume the products to be ...
*September 30, 2012*

**Pre-Calculus**

Composition of Functions If f(x) = 2x+1 find A. f o f(x) f(f(x)) = f(2x+1) f(2x+1) = 2(2x+1) f(f(x)) = 4x +2 B. f o f o f o f(x) ^ I dont get how to solve this one C. f o f o f o f o f ...o f(x) n functions of f ^ I also dont get how to solve this one given f(x) = ax+b and g(x...
*September 27, 2012*

**Pre-Calculus**

Composition of Functions f o g(x)=f(g(x)) --> I know that this is eqivalent to f(g(x)) Given f(x) = 2x+1, and g(X) = 3x+1 find:f o g(x)=f(g(x)) This is what I did, but I don't think Ive solved it correctly f(g(x)) = f(x-3) f(x-3) = 1(x-3)-3x+2 =x-3-3x+2 f(g(x)) = -2x-1 ...
*September 27, 2012*

**Pre-Calculus**

Operations with Functions write the function below as either a sum/difference/product/quotient of 2 r more functions a. h(x) = x^2+3x+9 How Would I do this? My teacher just did this f(x) = x^2 g(x) 3x+9 ^I dont really understand h(x)=(x+5)(x-3) how would I do this one? If h(x...
*September 26, 2012*

**Pre-Calculus**

Graphing Polynomials Decide whether each of the following is sometimes true, always true, or never true and explain reasoning. A. A cubic function has 2 different x-intercepts ^Never true, has to have 3? B. A cubic function has 3 x-intercepts ^ Always true C. A quartic ...
*September 26, 2012*

**Chemistry**

if you double the concentration of HCL acid, will that double rate of reaction? i have to explain in terms of the theory of collision. Wont doubling the concentration double the rate as well?
*September 25, 2012*

**Chemistry**

Thanks so much, does the amount of acid also matter? like 2.0M or 6.0M? and if its powdered that also increases the reaction rate right?
*September 25, 2012*

**Chemistry**

out of these conditions, which would result in fastest reaction? a. 2.0M HCL, powedered CaCO3 chip, 50 degrees celsius b. 6.0M HCL, CaCO3 chip, 25 degrees celsius c. 6.0M HCL, powdered CaCO3, 50 degrees celsius. d. 2.0M HCL, CaCO3 chip, 50 degrees celsius. Im guessing C ...
*September 25, 2012*

**maths**

(18/9(4-2)+5)
*September 23, 2012*

**Pre-Calculus**

-5x divided by x, how come that equals -5, but not -5x, how do the x's cancel out?
*September 18, 2012*

**Pre-Calculus need help in an Hour before test**

I still dont understand the whole process
*September 14, 2012*

**Pre-Calculus need help in an Hour before test**

The question in my book only has brackets around (x+5/2)
*September 14, 2012*

**Pre-Calculus need help in an Hour before test**

y=f(x+5/2) I timesd x+5 by 2 to get rid of 2 at the bottom and timesd y by 2. Then to get rid of 2 from y i divided it, and i got this. y=1/2f(x+5) however my teacher got y=f(1/2(x+5)) what did i do wrong?
*September 14, 2012*

**Pre-Calculus**

Need help with this question, dont get it. Given the relation x^2+3x=y^2-2y, what is the new relation if it has undergone: A. vertical expansion by 2 B. Horizontal expansion by 3 C. Vertical compression by 4/5 D. Horizontal compression by 1/5 E. Reflection over yaxis, vertical...
*September 13, 2012*

**Pre-Calculus Graphs expansions/compressions**

Need help with this question, dont get it. Given the relation x^2+3x=y^2-2y, what is the new relation if it has undergone: A. vertical expansion by 2 B. Horizontal expansion by 3 C. Vertical compression by 4/5 D. Horizontal compression by 1/5 E. Reflection over yaxis, vertical...
*September 12, 2012*

**Math**

Yes because capacity is how much a matter holds and the amount is also how much a matter can contain.
*June 12, 2012*

**Biology**

thanks a lot Ms. sue :)
*March 4, 2012*

**Biology**

Individuals whose characteristics are well-suited to their environment survive. Individuals whose characteristics ar not well-suited to their environment either die or leave fewer offspring. This principle Darwin called survival of the fittest. how i rewrite this definition in...
*March 4, 2012*

**biology tutor on jiskha**

thank you this just like jiskha? free site?
*February 22, 2012*

**biology tutor on jiskha**

i post my biology questions here today and few days ago no teacher reply. there not any biology tutor on here?
*February 22, 2012*

**biology**

any site i go onto that be animation site to find out about nucleic acids and protein synthesis? this chapter soo hard. codon, anticodon i need animation.
*February 22, 2012*

**biology what is DNA**

why is DNA replication necessary to life?
*February 22, 2012*

**biology**

why DNA replication necessary to life?
*February 21, 2012*

**Biology- DNA**

why dna replication necessary to life? i think it because it carry genetic information?
*February 20, 2012*

**biology anyone..**

no im not sure. i dont know if i scale. and how?
*February 16, 2012*

**biology anyone..**

please i need this by tomorrow. if nucleii are 3 micrometres long, how big are the cells? these r 2 questions i not get.
*February 16, 2012*

**biology - What Am I?**

this is for plant cell is it chloroplast?
*February 16, 2012*

**biology**

this part of organism usually found underground, what organele conspicuously absent?
*February 16, 2012*