Search results

  1. Z

    Equations Involving Vectorssss

    Equations Involving Vectorssss.... hey guys...stuck on a hw problem here... very simple not sure how to start... Here is the question: Find a vector equation and parametric equations for: The line through the point (1,0,6) and perpendicular to the plane x + 3y +z =5 can i...
  2. Z

    Infinite series please help.

    I'm having a little trouble with the following problem. here it is... Determinte whether a_n is convergent for... a_n = \frac{2n}{3n+1} How would i go about solving this? Can i just simply take the limit and use L'Hospital's rule to see if it diverges or converges? Or is it a little...
  3. Z

    Finding the Volume

    Hey everyone...I need to find the volume of the following shape... y= \frac{1}{x}, y=0, x=1, x=3 rotated about y=-1 ok so, i drew out the shape, and for the radius i came up with: r= \frac{1}{x} + 1 I think thats assuming that my radius is right, then the...
  4. Z

    Quick integral question

    ok here is the integral...sorry for the laziness... integral of dt/(t^4)-25 would this just turn out to be (t^4)-25 since you can bring up the denominator to the top as (something)^-1....then just take the antiderivative...? hope that makes sense edit: ok that wont I think i...
  5. Z

    Physics: the carnot cycle

    hey everyone, I need some help solving the following problem. I am kind of confused on where to start. here is the question from the book. A carnot refrigerator is operated between two heat reservoirs at temperatures of 320K and 270K. a) If in each cycle the refrigerator receives 415J...
  6. Z

    Finding F(1) and F'(1)

    Ok i have another problemo here... if F(x) = \int_{-x}^{x} \frac{dt}{1+t^2} Find F(1) and F'(1)....I need some assistance...the anti derivative is arctan(t) so then.... do i set that equal to f(1) and solve for t? and then for F', take the derivative and then solve for t again...
  7. Z

    Need help with this Integral

    Hey whats up..I need a little help with the following problem. If \int_{-\frac{\pi}{2}}^{M} \cos x dx= 1.5}, find M. How do I go about doing this? I know that...the anti derivative of cos is sin, and that \sin x \right]_{-\frac{pi}{2}}^{M} = 1.5 Any help would be greatly appreciated...
  8. Z

    Can you feel the HEAT?

    hey whats up guys, I need some help solving a hw problem for physics... here is the question. A gasonline engine has a power output of 180 kW (241hp). Its thermal efficiency is 28%. a) How much heat must be supplied to the engine per second? b) How much heat is discarded by the engine per...
  9. Z

    Integral OH YES!

    Ok, here is the integral i seem to be having some issues with. I know there's a very simple step im missing. \int_{}^{} e^x \sin(\pi x) dx i attempted to do this using by parts integration. I tried u = \sin(\pi x) so du= \pi \cos(\pi x) dx so then dv= e^x dx and v= e^x...
  10. Z

    Calorimetry copper pot problem

    Hey whats up, I am stuck on the following problem. a copper pot with mass of 0.5kg contains 0.170kg of water at a temperature of 20C. A 0.250kg block of iron at 85C is dropped into the pot. Find the final temperature assuming not heat loss. Ok, so Here is what i was thinking about...
  11. Z

    Really quick easy question

    Ok sorry for this..small, stupid obvious question...but here it is.. i need to solve for k in: e^10k = .75 So do i just take the natural log of both sides...and then the 10k should come down and i can just solve for k from that, right?
  12. Z

    Integrals, oh yeah

    integrals, oh yeah...... hey whats up, Ok so....i am having a little bit of a problem on solving the following integral... \int_{0}^{12} 50 + 14 sin\frac{\pi t}{12} dt would i use....trig substitution or by parts?.... :uhh: yeah...i need some help..thanks.
  13. Z

    Trig question confused

    hey whats up guys...i was trying to figure out this problem, but...I just cant see to get how to start. If someone can help me...that would be really nice. Its number 2 on this link... [Broken]
  14. Z

    Leaping the river

    here's the question...ill make it short a guy wants to leap a river. THe takeoff ramp is inclined at 53 degrees. The river is 40m wide, and the far bank where he is gonna land is 15m below the top of the take off ramp. The river itself is 100 m below the ramp. Ignoring air resistence, find...
  15. Z

    Hit the Monkey

    Im having issues with this problem... A zookeeper with a tranqualizer dart gun and a monkey (1.5kg) are both 25 m above the ground in trees 90 m apart. Just as the zookeeper shoots the gun, the monkey drops from the tree. What must the minimum muzzle velocity of the dart have been for it to...
  16. Z

    Win the Prize!

    Ok here is the question.. In a carnival you win a stuffed giraffe if you toss a quarter in a small dish. Dish is 2.1 m away from your hand in a shelve above the point where the coin leaves your hand (y). Initial velocity must be 6.4 m/s. a) find y and b) what is the vertical component of...
  17. Z

    Physics question: velocity

    Ok, here is the question. A swimmer dives off a cliff with a running horizontal leap. What must her minimum speed be just as she leaves the top of the cliff so that she will miss the ledge at the bottom which is 1.75 m wide and 9.00m below the top of the cliff. which equation would i use...
  18. Z

    Angle of line of sight for a vertically lauched rocket

    Hey...whats up, ok... here's the problem. A rocket is launched vertically from a point on the ground that is 100 horizontal meters from an observer with binoculars. The rocket is rising vertically and its height above the ground (in meters) is given by : y(t)=60t-5t^2 Two seconds after...
  19. Z

    Finding Critical numbers

    Hi, i was wondering if anyone could help me. The problem says find the critical numbers of f... f(x) = 2x^3 + 15x^2 - 36x +1 ok i found f ' .....6x^2 + 30x-36, Now how do i start on finding the critical numbers? Do i have to take the second derivative?
  20. Z

    Help with Final Exam

    Hey whats up guys... Ok i have a calculus final that covers limits, derivatives, and applications of differentiation. Can you give me any pointers or tips on what i should focus on most. Im allowed a sheet of notes, so far i put all the limit laws, and the differentiation rules on it. what...
  21. Z

    ?Parametric equations?

    ??Parametric equations?? hey whats up, ok i have a question on differentiating parametric equations. The question says to find the equation of the two tangent lines to the curve. here's the equations... x = 6 cos t y= 2sin2t Now, after i differentiate them, do i just plug in...
  22. Z

    Solving for x

    hi, I was wonderin how i would solve for X in the following equation... 0 = 60x^2 - 90x^4 If i do add 90x^4 from both sides....and then go about solving for x, i get 1/x, which is the same as -x...and then i have to take the square root of a number, and i cant do that with a negative...
  23. Z

    Finding sides of triangles

    I was wondering if you can find the sides of a right triangle if you only know the angles of the triangle...i couldnt think of a trig ID or any law..if there is, id like to know it, thanks.
  24. Z

    Quick derivative

    hey guys, I need to find the derivative of this function, do i use the chain rule and the product rule? and for the stuff inside the parenthesis, how do i differentiate that? the derivative of x is just 1....but since its a fraction, would it be as simple as that? please help, thanks...
  25. Z

    Can anyone help?

    I need help with the following problem... The volume (in gallons) of water in a tank at time t seconds is given by the function V(t) = e^{2t} - 12t^2+100 where 0 \leq t \leq 3 a) when is the water flowing out of the tank at the fastest rate? At what rate is it flowing at this time...
  26. Z

    Find the cost function C(x)

    I was wondering if anyone can help me on this problem... A truck burns fuel at the rate of G(x) gallons per mile. Where G(x) = \frac {1} {32} \left(\frac {64}{x} + \frac {x}{50} \right) a. Find the cost function C(x) if the truck takes a 400 mile trip. Assume that the cost of fuel...
  27. Z

    HELP me please

    HELP me please!!! Hi, I am having trouble figuring out how to tackle this problem, it would be great if anyone can help! :eek: Here is the problem... The three containers shown below (sorry, i can only describe them and not draw them here, i'll describe em at the bottom) are all initially...
  28. Z

    Use implicit differentiation to find the points of tangency

    Please Help!! Ok, im having problem with an Implicit differentiation problem... Two tangent lines to the hyperbola 9x^2 - y^2 =36 intersect at the y-axis. Use implicit differentiation to find the points of tangency. Ok so i implicitly differentiated this function and i came up with y'=...
  29. Z

    Parametric CurvesHELP

    URGENT help needed please..... I have been having problems with this says... A graph of the Lissajous figure is given by the paraetric equations: x=sin2t and y=cost Show that the curve has two tangents at the point (0,0) and find their equations Can someone please help...
  30. Z

    Points of tangency

    I have the following function given, and I need to find the points of tangency... Two tangent lines to the huperbola 9x^2 - y^2 =36 interesect at the y-axis. Use implicit differentiation to find the points of tangency. Ok so i multiplied both sides by dy/dx, and solved for y'...i got...