Karl's Calculus Forum: Feb/Mar 2004
© 2004 by Karl Hahn
© 2004 by Karl Hahn
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Hi I have a huge problem, my friends and I can't figure out how to get the answer to the following quesion:
cos 7(pie)/8
Anyone that could help me out with this, it would be appreciated!!!!!!
Thanks! Dana Vancouver, BC Canada - Wednesday, March 31, 2004 at 17:15:22 (EST) |
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Hi I have a huge problem, my friends and I can't figure out how to get the answer to the following quesion:
cos 7(pie)/8
Anyone that could help me out with this, it would be appreciated!!!!!!
Thanks! Dana Vancouver, BC Canada - Wednesday, March 31, 2004 at 17:10:09 (EST) |
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Reply to Andrew:
Use the product rule and the
chain rule to do this one. You have
the product of
x5 with
sec(1/x). The second factor is a composite of
taking the secant with taking 1/x. Apply the chain rule to find
the derivative of the second factor. Then use that together with the
product rule to find the derivative of whole thing.
Derivative of x5 is
5x4.
The derivative of the secant is the secant times the tangent. The derivative
of 1/x is -1/x2.
See if you can put it all together.
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Trying to figure out the answer to the question:
find dy/dx for the equation:
y = x^5 sec (1/x) Andrew USA - Friday, March 26, 2004 at 03:11:14 (EST) |
Reply to Janet:
I shall assume no air resistance. Ayida's velocity after falling x
meters is given by
___
v = Ö2gx
If she is at h meters height going v0 meters/sec
and she fires the rocket, then her velocity as a function of time will be
v(t) = v0 - atwhere a is the acceleration of the rocket. Her height as a function of time after firing the rocket will be x(t) = (1/2)at^2 - v0t + hUse the first equation I gave to write v0 as a function of the distance fallen,
To find the maximum height, replace 100m with H.
Remember that t cannot exceed 10 seconds. Use the same
methods to find H when you force |
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At a publicity event, Ayida, a stuntperson, will jump out of a helicopter with a jetplack on her back. The jetpack allows her to achieve a net upward acceleration of 4.4m/s2 for a single interval of maximum length 10s. Ayida wants to time the use of the jetpack so that she lands with zero velocity.
a)If the helicopter is 100m high, when should Ayiya turn on her jetpack? when will she land?
b)If the helicopter is 200m high, when should Ayida turn on her jetpack? when will she land?
c)What is the maximum height from which Ayida can jump to land at zero velocity?
Thank you so much to anyone that can help, it is greatly appreciated! Janet Canada - Sunday, March 21, 2004 at 15:35:58 (EST) |
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Sorry - forgot to say "a big thank you for the help"! - Keith Keith USA - Sunday, March 07, 2004 at 18:58:26 (EST) |
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I'm trying to figure out:
Volume of the solid generated by revolving around the y-axis.
This solid is a donut with the center at 4,0 (x=4,y=0) with radius 1.
Any suggestions how to set up formula? Keith USA - Sunday, March 07, 2004 at 18:24:40 (EST) |
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I need help with this following problem
determine the point(s) at which the graph of the function has a horizontal tangent
f(x) = (x^2) / (x^2 + 1)
I was out of class 2 weeks with the flu and missed a lot. I think that I have caught up with most of the problems, but this one is giving me problems.
Thank you. jade USA - Saturday, March 06, 2004 at 10:37:10 (EST) |
I really need help solving question #2 from the following webpage:
http://www.math.psu.edu/anand/M141/applied2/I've attempted to solve this, but looking at my answers, I'm not overly confident. In part a, I'm suppose to prove that tractrix somehow, and in part b, I believe I am to just integrate that given equation... But I'm not 100% sure (especially with part a)... I'd be eternally grateful to any help given. Thanks. :) PM FL USA - Friday, March 05, 2004 at 00:07:52 (EST) |
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Dear Sirs,
I am 63 years old. I have had mechanical, electrical and nuclear engineering (40 years ago). It was via a special education program authorized by an act of Congress for the development of nulcear power in the military. For that reason I was not degreed and didn't get everything that a full 4 year program would have given. The biggest thing I missed was calculus. We only got introductory calculus and I have never even used that.
I now have a calculus project I am seeking to get done. It involves integration of spheres and would need graphics and adequate scripting such that others could follow the process, with a final plot of data over several seperation distances of the spheres.
I don't have a lot of money but I would be willing to pay a couple hundred to get this done. Is there anyone here that would be interested or can you direct me to somewhere that I might find a collaborator.
A physicist friend of mine did 8 pages of calculus back in the 60's and concluded what I was trying to prove was valid but I am now being told his presentation is difficult to follow.
Thank you in advance for any assistance.
Dan K. McCoin
lmccoin@elp.rr.com
Dan K. McCoin El Paso, Tx USA - Wednesday, March 03, 2004 at 09:58:19 (EST) |
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im doing an initial value problem, but the question is dy/dx = 2y^2....i have no clue how to do it when y is the variable....doing it with x is easy...thank you Jon dallas, USA - Sunday, February 29, 2004 at 16:50:12 (EST) |
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I would like to ask about the partial integration for repeated and non-repeated? Salvatierra, Teodoro Butuan, Phils - Friday, February 20, 2004 at 00:30:07 (EST) |
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airhead,
Your question about kepler's law. Once you determine the major axis of a planet's orbit you can identify where the 2nd foci will be. You can determine the length or orbit of a planet is shown by the square of the period of revolution a planet takes, this is in proportion to the CUBE of the length of the major axis of a planet's orbit.
Kind of confusing but just look at it this way.
if you know how long the major axis is you can determine that the 2nd foci has to be equadistant from the ellipse lengths that first foci is.
ben USA - Thursday, February 19, 2004 at 17:44:44 (EST) |
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To Just trying to understand.
here's an easy way to understand how to take the devirative of ln's
say you have ln(x). the devirative is 1/x. See how its just the recipracol over the devirative?? hope that helps.
Your going to need to do more because you have a QUOTIENT *wink wink. after you take the reciprocal of 2x/x+1. Remember the rule of taking quotient deviratives and multiply the two terms together. ben USA - Thursday, February 19, 2004 at 17:33:18 (EST) |
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well sherry here's a trick graph the function with a calculator and just take a look at the graph.
if you want to know mathmatically how to do it. Multiply those terms together and you'll find f(x). Now take the devirative of whatever the function turns out to be with respect to x. Set f(x)=0 and find whenever x=0 that will give you values where you know there has to be a min or max. To test whether its a max or min take one of your values for x and check close to it on both sides if the function is less on both sides you've got a max, if its greater on both sides you have a min. Hope I could help ben ames, ia USA - Thursday, February 19, 2004 at 17:28:17 (EST) |
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Hey guys,
I was just wondering if anyone knew how I would go about doing this question. I tried the "table of method" way and it was not working very well.
Graph the following polynomial function and state its local maximum and local minimum.
f(x)= (x-2)(x+3)(x-1)
Thanks a lot =) Sherry Houston, TX USA - Tuesday, February 17, 2004 at 17:38:47 (EST) |
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Please help me find the derivative of the function: f(x)=ln 2x/x+1
I would really appreciate your help!
Thank you! Just Trying to understand Toronto, ON Canada - Saturday, February 07, 2004 at 18:25:08 (EST) |
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hey can i get some help with this problem... i need to find the integral of
( x^3+3*x^2+3*x-4)/(x^2*(x+3)^2) dx. nick USA - Thursday, February 05, 2004 at 18:37:37 (EST) |
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I have a calculus problem that i can't figure out if someone could offer some help, please!!!
The speed S of an object proir to collision can be estimated by the length L of the skid mark left by the tires of object when applying brakes; therefore, speed is a function of length. The relationship between the speed and the length of the skid mark is given by: S(L)=In(3x)-0.0081.
Use your graphing calculator to determine graphically the largest delta>0, such that for any L such that (5-delta, 5+delta), S(L) such that (S(5)-E, S(5)+E), where E=0.010. Provide a graph including upper and lower bounds for L and S(L).
First of all what is In in the function? confused USA - Thursday, February 05, 2004 at 04:35:33 (EST) |
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