Posts by kieran

Total # Posts: 51

  1. Maths

    karen decorated her mother's birthday cake. one-third of candles are pink, three-eights are yellow, one-quater are blue and the two remaining candles are white. calculate (a). the fraction of candles that are white. (b). the total number of candles on the cake. Need answer...
  2. Chemistry

    Not A
  3. calculus

    the area of a rectangle is A=lw. Further suppose l=2w. calculate dA in terms of the differential dw. does this just mean to get the derivative of 2w^2
  4. calculus

    determine the cubic function with 1 point of inflection and no relative minima or maxima.
  5. calculus

    that is how I worked it out as well but I did not know if it was that simple I find ways of making simple things hard sometimes thanks for the help
  6. calculus

    Calculate the area between curves y=e^x and y=-e^x on the interval [0,1]
  7. calculus

    need some help im doin antiderivatives it has (2-x^2)^4xdx i understand how to do it for the most part but i come up with 1/5(2-x^2)^5+c the book has a answer of -1/10(2-x^2)^5+c how what am i doing wrong
  8. Calculus

    How do you go from ln(x^10)+e^ln(x) to 10ln(x)+x
  9. Calculus

    if you have g(x)=ln(x^10)+e^ln(x) would you just get 1/x^10+e^ln(x) or am i wrong the way it was explained to me that with e the derivative is just wat it is you don't change it
  10. calculus

    y=x^3-3x. Fill out the following table and then make a rough sketch of the graph. I can make the sketch just having trouble understanding what is wanted. y=0 when y'=0 when Relative Max(s) Relative Min(s) y'>0 on the interval(s) y'<0 on the interval(s) y is ...
  11. Calculus

    y=x^3-3x. Fill out the following table and then make a rough sketch of the graph. I can make the sketch just having trouble understanding what is wanted. y=0 when y'=0 when Relative Max(s) Relative Min(s) y'>0 on the interval(s) y'<0 on the interval(s) y is ...
  12. Calculus

    A closed box is to be rectangular solid with a square base. If the volume is 32in^3, determine the dimensions for which the surface area is minimum.
  13. Calc

    how did you go from 0= 1/6 (3+-ã3)
  14. Calc

    a box with an open top is to be made from a rectangular piece of tin by cutting equal squares from the corners and turning up the sides. The piece of tin measures 1mx2m. Find the size of the squares that yields a maximum capacity for the box. So far i have V=(1-2x)(2-2x)x
  15. Calculus

    a property owner wants to build a rectangular enclosure around some land that is next to the lot of a neighbor who is willing to pay for half the fence that actually divides the two lots. If the area is A, what should the dimensions of the enclosure be so that the cost to the ...
  16. Calculus

    By Kirchoffs voltage law the sum of the voltage in the circuit. Consider the circuit with variable resistor R. 5V 10ohms R A. find a relationship between I and R in the circuit using E=I R and kirchoffs voltage law. B. the power to a resistor is given by I^2R watts write P as ...
  17. Calculus

    thats right. i always overthink things never even looked at the T's cancelling
  18. Calculus

    The efficiency E of a screw is given by E=T(1-0.35T)/T+0.35 where T is the tangent of the pitch angle of the screw and 0.35 is the coefficient of friction . For what value of T>0 is the efficiency the greatest?
  19. Calculus

    how do you get 2av should that be zero since a is a constant or did i miss something in class
  20. Calculus

    The drag on an airplane traveling at velocity v is D=av^2+(b/v^2) where a and b are positive constants. At what speed does the airplane experience the least drag. I have so far that D'=-2b/v^3 do i set this equal to zero then i get 0=-2 don't think that is the right ...
  21. Calculus

    so the parenthasis means including and the bracket means its open or how does this work
  22. Calculus

    Find the intervals on which the given function is increasing and decreasing. y=-x^2-2x y'=-2x-2 critical point x=-1 Increasing [-infinity,-1) Decreasing (-1,infinity] is this the correct way of writting this wiht the brackets
  23. Algebra 1

    Percent to a fraction, all you have to do is lets take 85% we put 85/100. so just take your percent set it over 100 and reduce we get 17/20
  24. Algebra 1

    a decimal to a percent ok so allyou have to do is take the decimal .625 and multiply by 100 you use 100 because 100% is going to give you the percentage out of 100 which is what we use. so by multiplying by 100 we know that we just need to move the decimal two places to the ...
  25. Algebra 1

    ok so for instance you have 5/8 all you need to do is divide 5 by 8. whic if you do the math you will get .625. Or even easier to use things that are easy to divide by so 6/10 ok so if you divide 6 by 10 all you have to do is move the decimal so you get .6. You use the same ...
  26. MATH

    y=x-a/bz
  27. Calc

    if the velocity can be expressed as v(t)=1-∛t what is the acceleration function. so i started by bringing in acceleration formula a=v1-vo/t1-to took my velocity function and found the derivative. v=-1/3t^2/3 have i started it correct so far and where do i go from here ...
  28. Calc

    I could be wrong but im not sure i came up with 1/4
  29. Calc

    sorry about that a shouldnt b in there it should be f(x)=(2x^2)+(1/sqrt(x))+[(1/4)x^3]-x+1 the a thing was supposed to be a sqrt but i guess it doesnt copy over from work
  30. Calc

    Just making sure im doing things right. suppose that f(x)=2x^2+1/ãx+1/4 x^3-x+1 Caclulate f '(1) So far i have 4x+(ãx^-1)+3/4 x^2-1+0 then i substituted my 1 in and came out with 4 3/4
  31. Math

    range and domain of f(x)=x^2-x-6/x-3 someone gave some input earlier but just looking to get a little more in depth help thanks
  32. math

    ok so i havent done domain and ranges for a while so i need some help this is just a generic question but i want to make sure i know how to do them before starting calc so can someone please explain how i would heres a function f( t) = t+ 3 /(t2 – 5t – 66),
  33. Math

    A street that is 164m long is covered in snow. City workers are using a snowplow to clear the street. The snowplow has tires that are 1.5m in diameter. How many times does a tire have to turn in traveling the length of the street?
  34. AP Physics

    The surface of the sun has a temperature of about 6.0 103 K. This hot gas contains hydrogen atoms (m = 1.67 10-27 kg). Find the rms speed of these atoms.
  35. science

    what describes an allele that only controls a characteristic if present on both chromosones in a pair (9 letters)
  36. science

    a section of dna which codes for the synthesis of a protein is called what ? (4 letters )
  37. genes

    how is gene therapy providing a treatment for cf
  38. genes

    name two of the negative implications of the human genome project
  39. genes

    name two of the positive implications of the human genome project
  40. genes

    explain the arguments against genetically modified organisms
  41. genes

    explain the advantages for genetically modified organisms
  42. science

    still stuck on this crossword - what is another word for natural, from living matter ( 7 letters) thank you
  43. science

    i have to do a crossword for school and need help on the following question (answer 9 letters)what describes all the organisms within an environment and their relationships with each other and the environment please help
  44. science

    i have to do a crossword and the question is (answer 9 letters)what describes all the organisms within an environment, and their relationships with each other and the environment please help
  45. science

    what is the mass or organic material in an organism or population
  46. year 7 science

    what is the scintific name for rainbow
  47. dimensions

    I need to know the dimensions of a califorian King sized bed does anyone know? 72"W X 84"L http://www.esleepshop.com/bed_frames_bysize.htm?gclid=CKnm1dvux40CFRlmWAod-GbvLQ I Googled California king-sized bed and found this site. Scroll down to find that this sized ...
  48. absolute value

    when you are solving an equation involving absolute values, do you have to have both negative and positve solutions?? not necessarily, it depends on the equation. e.g.#1 │2x-1│ = 5 then (2x-)=5 or -(2x-1)=5 x=3 or x=-2 here you have a positive as well as a negative...
  49. Slope

    anyone know a good definition for slope?? google "slope" and its on wikipidia Thank you for using the Jiskha Homework Help Forum. Before you look in any good dictionary, be sure you know the part of speech. The word "slope" can be a verb, an adjective or a ...
  50. Math

    what exactly is the midpoint formula?? I am taking an oline summer school course in geometery and every website I go to tells me something different for any two points (a,b) and (c,d) the midpoint is ((a+c)/2,(b+d)/2) in words, add up the x's and divide by 2, then add up ...
  51. pigments

    What are the three accessory pigments in plants? http://en.wikipedia.org/wiki/Phycobilin http://en.wikipedia.org/wiki/Carotene http://en.wikipedia.org/wiki/Xanthophyll http://en.wikipedia.org/wiki/Phycoerythrobilin