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  1. C

    Find the Region enclosed

    lol yeah, i didnt know how to insert a and b into the integral sign. thanks for the help
  2. C

    Find the Region enclosed

    ah, 0.9pi is equal to 162 degrees right? i graphed it using my calculator. don't know why, but i thought of 0.9pi as 2.872433. so would my equation look like this... \int 4cos(x) -3sin(x) (a=0,b=.295\pi) + \int 3sin(x) - 4cos(x) (a=.295\pi,b=9\pi) is that correct?
  3. C

    Find the Region enclosed

    Find the area of the region enclosed between y=3sin(x) and y=4cos(x) from x=0 to x=0.9\pi . does that mean the integral would like this: \int 4cos(x) - 3sin(x) (a=0, b = 0.9*pi) is that correct?
  4. C

    Sketch Region enclosed

    k checked that part and got the same signs, so what is wrong with my answer? did i set up the equation correctly? (is there a Ti-83 plus program i can use to check my answer? or is there any math program for the computer that would do this for me?
  5. C

    Sketch Region enclosed

    Sketch the region enclosed by x+y^2=12 and x+y=0. Decide whether to integrate with respect to x or y. Then find the area of the region. first thing i did was solve for x for each equation then set them to each other and got: 12-y^2=-y y^2-y-12=0 found the points of intersection of y...
  6. C

    Who's using masteringphysics.com here?

    it's alright, but yea it doesn't prepare you for questions on masteringphysics. it's totally different questions
  7. C

    Schools out there uses maple

    thanks alot, works perfectly.
  8. C

    Who's using masteringphysics.com here?

    im doing mastering physics, but i have "Physics with Modern Physics for Scientist and Engineers, Third Edition". but yup, we use the same site
  9. C

    Schools out there uses maple

    dont know how many schools out there uses maple, but let me ask my question anyway. maple is a program that does math calculation and other stuff, it's pretty impressive. you can use it to do integrals and stuff. here's my question using maple: 1.) Let f(x) =x^2 and g(x) = x*e^(-x/2). Find...
  10. C

    Newton's Laws and net force

    please help me check my answers, cause if i get one answer wrong, it's a big point deduction. i don't really like doing my homework online. here it goes... 1.) An object cannot remain at rest unless which of the following holds? A.)The net force acting on it is zero. B.) The net...
  11. C

    Projectile Motion Leap Question

    sorry to go back to a question you already answered, but how did you find the time it will take? i found that V(0)x = 3.5m/s V(0)y = 0 m/s would you use this to find the time? x(0) would be 4.5 since it's the initial height right? x(t) = x(0) + v(0)t + 1/2(a)(t)^2? 0 = 4.5 + 3.5t +...
  12. C

    Trigonometric substitution integrals

    i get it now! thanks. the trig. sub. should be: \frac{\sqrt(8)tan(t)}{\sqrt(7)}
  13. C

    Trigonometric substitution integrals

    \int \frac{x^2}{\sqrt{(7x^2 + 8)}} ok this one is a bit hard...i been thinking about this one for awhile. can i do \int \frac{x^2}{\sqrt{(7x^2 + 7 + 1)}} ? sin^2(\theta) + cos^2(\theta) = 1 so... well i know it's sec^2(\theta) from solving the previous problem \int...
  14. C

    Trigonometric substitution integrals

    lol, thanks. i just made a dumb mistake
  15. C

    Trigonometric substitution integrals

    what would be the appropriate trigonometic substition for the following: 1.) \int(7x^2-7)^{3/2}) dx 2.) \int \frac{x^2}{\sqrt{(7x^2 + 8)}} ok i have a book with a list of trigonometric functions in front of me, but i don't get it. i don't see anything that i can sub in for. ok i...
  16. C

    Height of a baseball - kinematics

    A major leaguer hits a baseball so that it leaves the bat at a speed of 31.4 m/s and at an angle of 38.1 above the horizontal. You can ignore air resistance #1: At what two times is the baseball at a height of 10.9s above the point at which it left the bat? Give your answers in ascending...
  17. C

    Free fall acceleration flowerpot problem

    yea i did use that equation, -1.9 = v(0)(0.42) - 4.9(0.42)^2 solved for v and plugged it into vf^2 - v(0)^2 = 2gh dont know why i get a different answer i even used your formula and get -2.764
  18. C

    Evaluate the indefinite integral.

    \int sin(7x)sin(13x)dx i just need to know how to start this, i can't use u-du... i can't borrow anything... so how would i start this?
  19. C

    Math sin integral help

    thank you everyone, that really helped. I am so glad i know how to do these problems now, it feels really goood. thank you agian
  20. C

    Free fall acceleration flowerpot problem

    didnt i set v(0) to zero for the second equation? can someone tell me if h = -.308m is correct?
  21. C

    Free fall acceleration flowerpot problem

    coconut, i have the same problem as you(with different numbers), are you doing your homework on mp also? -1.9 = v(0)(0.42) - 4.9(0.42)^2 after solving this for v(0) i get -2.46m/s (-2.46)^2 =2(-9.8)h h = -.308m does that look right? seems incorrect to me
  22. C

    Calculus III

    everybody tells me that CalIII is easier than CalII. anyway, everything is easy in the beginning
  23. C

    Math sin integral help

    why did you remove cos^2(4x)? i don't get it for example: = \int (1-cos^2(4x)) * cos^{10}(4x) * sin(4x) dx you use 1 to multiply cos^{10}(4x) * sin(4x) dx then you use cos^2(4x) to multiply cos^{10}(4x) * sin(4x) dx right? that's how i got cos^{12}(4x)cos^2(4x)sin(4x)dx... am i...
  24. C

    Math sin integral help

    \int sin^3(4x)cos^{10}(4x) dx ok i know that i need to borrow the a sin, cause the sin has an odd power \int sin^2(4x)cos^{10}(4x) sin(4x)dx ok used one of the trig ids. on sin^2(4x) = \int (1-cos^2(4x)) * cos^{10}(4x) * sin(4x) dx =\int cos^{10}(4x)*sin(4x)dx - \int...
  25. C

    Free fall question

    what is -ve? and why is the answer for problem A.) a positive answer? after inserting -6.35, i get a negative answer. so... why is the answer positive instead of negative? "For the last part, don't forget that you begin with a velocity of -6.35 m/s" are you talking about problem C.)...
  26. C

    Free fall question

    A student throws a water balloon vertically downward from the top of a building. The balloon leaves the thrower's hand with a speed of 6.35m/s . Air resistance may be ignored, so the water balloon is in free fall after it leaves the thrower's hand. A.) What is its speed after falling for a...
  27. C

    Evaluate integration

    ok i know how you got \int{\frac{t^{15}}{15} \frac{dt}{t}} = \int{\frac{t^{14}}{15}dt but how did you get \int{\frac{t^{14}}{15}dt = \frac{t^{15}}{225} i know you got the anti-derv. of it, and i tried to look in my book for a form like that, but i can't find it. can you explain to me...
  28. C

    Man catching a bus

    so your telling me to slove for cmin^2 -2ab =0 right? so cmin = sqrt(2ab). is that the correct answer?
  29. C

    Man catching a bus

    Inserting the formulas you found for xman(t) and xbus(t)into the condition xman(t catch) = xbus(t catch), you obtain the following: -b + ctcatch=1/2at^2catch Intuitively, the man will not catch the bus unless he is running fast enough. In mathematical terms, there is a constraint on the...
  30. C

    Man catching a bus

    your right,thanks. i have another question what is Xbus(t) the position of the bus as a function of time? using the formula x(t) = x(0) +v(0)t + (1/2)at^2 x(t) = b +v(0)t +(1/2)ct^2 hmm what would be v(0)t? and is my setup correct? and what should i do next?
  31. C

    Man catching a bus

    A man is running at speed c (much less than the speed of light) to catch a bus already at a stop. At t=0, when he is a distance b from the door to the bus, the bus starts moving with the positive acceleration a. Use a coordinate system with x=0 at the door of the stopped bus i have two...
  32. C

    Evaluate integration

    what do you mean? your setup is just like mines
  33. C

    Evaluate integration

    Evaluate \int t^{14} ln(t) dt using integration by parts and formula uv-\intv du u=ln(t) du=1/t dv=t^14 v=t^15/15 lnt*t^15/15-\intt^15/15*1/t lnt*t^15/15-t^14*log(t) i don't know what I am doing wrong, please help
  34. C

    Hard physics problem

    A sled starts from rest at the top of a hill and slides down with a constant acceleration. At some later time it is 14.4 m from the top; 2.00 s after that it is 25.6 m from the top, 2.00 s later 40.0 m from the top, and 2.00 s later it is 57.6 m from the top. Question A.) What is the...
  35. C

    Velocity vector

    If r^{\rightarrow} = bt^2i+ct^3j, where b and c are positive constants, when does the velocity vector make an angle of 45.0^o with the x- and y-axes? i & j are vectors. i have no clue on how to start it, can anyone give me a hint?
  36. C

    Find the length of the side of a cube of iron

    1.) 3.94 cm 2.) 2.44 cm where are you from? are you doing the same homework as i am? if so, maybe we can help each other out.
  37. C

    Find the length of the side of a cube of iron

    thank you everyone for the help, i finally get it! sorry for all the questions
  38. C

    Find the length of the side of a cube of iron

    i got x=.0610687 when trying to find the volume. so shouldn't it be x=6.11\times 10^{5}m^3=V instead of x=6.11\times 10^{-5}m^3=V? cause x=6.11\times 10^{-5}m^3=V =.0000611 right? so...V=.0610687 = L^3 L=\sqrt[3]{.0610687} L = .3937974428 m^3 <-- that doesn't seem to convert to around...
  39. C

    Find the length of the side of a cube of iron

    let me show you what i done. cross multiply, so i get 7.86000kgx=0.480kg x=.0610687 <-- is that the volume? that doesn't look right, i know I am doing it incorrectly. why did you convert 480g to .480? and what should i do with 1m^3? am i suppose to do unit conversions first? I am sorry, I...
  40. C

    Find the length of the side of a cube of iron

    ok I am still confuse, but let me try. ok for the first question, V=L^3 right? so... V= 7.86 X 10^3kg and L isn't defined? where does the 480 g come in?
  41. C

    Integration by parts

    hi, i would like help on a problem i am currently stuck on. \int(e^x)/(1+e^(2x))dx <-- it's suppose to be \int (e^x)/(1+e^(2x))dx using integration by parts, here's what i done: u=e^x du=e^x dv=(1+e^(2x)) v = (need to use anti-differentiation, which i don't remeber...) can i...
  42. C

    Find the length of the side of a cube of iron

    Iron has a property such that a 1.00m^3 volume has a mass of 7.86 X 10^3kg(density equals 7.86 X 10^3kg/m^3). You want to manufacture iron into cubes and spheres. 1.) Find the length of the side of a cube of iron that has a mass of 480 g. 2.) Find the radius of a solid sphere of iron...
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