# Search results

1. ### Differentiate: r=r cos(theta)i+r sin(theta)j

A few Multiple function product rule refresher videos later... I believe the 1st term should go from: -r \frac{d\theta}{dt} \sin(\theta) to: - \left( \frac{dr}{dt} \frac{d\theta}{dt} \sin(\theta) + r \frac{d}{dt}(\frac{d\theta}{dt} \sin (\theta)) \right) - \left( \frac{dr}{dt}...
2. ### Differentiate: r=r cos(theta)i+r sin(theta)j

Ah yes, it's been 5 years since I typed anything in LaTeX either, but I wrote it correctly on my paper. Now I need a refresher on getting the second derivative of the equation. I have: \vec{r} = r \cos(\theta) \hat{i} + r \sin(\theta) \hat{j} \vec{v} = \left( -r \dot{\theta} \sin(\theta) +...
3. ### Differentiate: r=r cos(theta)i+r sin(theta)j

Ok, so I don't need to chain rule the 1st cosine factor, and adding the chain rule on the cosine factor on the left: \cos(\theta) \cdot \frac{d\theta}{dt} gives: \frac{dx}{dt} = \frac d {dt}\left(r\cos(\theta)) \right) = \frac {dr}{dt} \cos(\theta) + r \cdot \left(\cos(\theta) \cdot...
4. ### Differentiate: r=r cos(theta)i+r sin(theta)j

I get that r is the magnitude of \vec{r} Both r and \theta are functions of time. Let me start with only the x-side of the equation: x = r \cos (\theta) Applying the product rule to r and \cos(\theta) yields: \dot{x} = r (-\sin)(\theta) + \dot{r} \cos (\theta) And adding the...
5. ### Differentiate: r=r cos(theta)i+r sin(theta)j

Homework Statement This is a problem from Dynamics but I'm mostly having trouble with the calculus. Derive an expression for the position, velocity, and acceleration of a machine in terms of: r, \dot {r}, θ, \dot{θ}, \ddot{r}, \ddot{θ}, . r = length of the arm θ = angle of the arm to the...
6. ### Mechanical Engineering degree/transfer student Q's, advice highly recommended.

So, i assume math 111 is College Algebra/ Pre-Calc, and 112 is Trig. There are usually several General-Education classes that have to be taken as well as ME specific classes, you can always take those while you complete the math sequence. I do not know your specific course requirements (or...
7. ### Mechanical Engineering degree/transfer student Q's, advice highly recommended.

Well, from a quick google search I think Math 65: Developmental elementary algebra, and Math 95: Developmental Intermediate Algebra, but I'm not sure if your school allows you to take Calculus 1 after that. I do not know if you can finish a ME degree before your GI bill runs out, but it does...
8. ### Can I Become An Engineer With a Family?

I am 32 and married to my wife for almost 3 years and we are expecting twin boys due in October. I have been attending CC for 2 years part time getting my gen-ed requirements, and the first 2 years toward a mechanical engineering degree, out of the way. And I may be here another 2 years before...

Thanks.
10. ### Post Your Summer/Fall 2012 Class Schedules

Summer: Work full time, Gen Ed......Macroeconomics Fall: Continue working full time, Linear Algebra Calc-based Physics 1 (online, including lab) Become Daddy of twin boys!
11. ### Programs Majoring in Engineering what is the sacrifice like?

I understand your frustrations, and yes this does seem like a big sacrifice. I, too, hope it will be worth it in the end. I currently work 45hrs per week and attend community college part time (10hrs of online and night classes). I finally have most of my gen-ed classes out of the way, but...
12. ### Find the inverse of the polynomial.

I am still a little confused, but thank you very much for your help. I need to find and practice another one of these.
13. ### Find the inverse of the polynomial.

In this formula?(f^{-1})(a)=\frac{1}{f'((f^{-1})(a))} (f^{-1})(a)=\frac{1}{f'(1)} then f'(1)=\frac{1}{2}(25)^{-\frac{1}{2}}(6) equals 3/5, and the inverse is 5/3. So, is this the way I should go about these kind of problems?

f(1)=5
15. ### Find the inverse of the polynomial.

My choices were 2/3, 5/3, 4/3, or 7/3. I guessed 2/3, but was wrong and the correct answer was 5/3. My guessing needs work.
16. ### Find the inverse of the polynomial.

Well, f(5)=\sqrt{177}\approx13.304 So, is the inverse 1/13.304, but then what is the derivative of the inverse? Or the inverse of the derivative??? at a=5f'(x)=\frac{1}{2}({x^{3}+x^{2}+x+22})^{-\frac{1}{2}}(3x^{2}+2x+1) f'(5)=\frac{66}{2\sqrt{177}}...
17. ### Find the inverse of the polynomial.

Homework Statement Find (f^{-1})'(a) of: f(x)=\sqrt{x^{3}+x^{2}+x+22} ; a=5. Homework Equations (f^{-1})'(a)=\frac{1}{f'((f^{-1})(a))} The Attempt at a Solution Well, I know to find an inverse: I need to set the equation equal to y, solve for x, then swap x and y. But I don't...
18. ### Using Alternate texts?

I am just starting Calc 2 using the Stewart Calculus book, but I'm finding it harder to understand than the book I used for Calc 1 (Calculus by Briggs and Conchran). I wish I still had that book. I think I will be buying an additional Calculus book to try and get a different perspective on...

20. ### Implicit exponential differentiation?

So, \frac{d}{dx}(ye^{x})=ye^{x}+y'e^{x} giving me, xe^{y}y'+e^y+ye^{x}+e^{x}y'=0 y'(xe^{y}+e^{x})=-e^{y}-ye^{x} y'=\frac{-e^{y}-ye^{x}}{xe^{y}+e^{x}} at point (0,1). slope=(-e-1)
21. ### Implicit exponential differentiation?

Yes, I now realize I need to use both rules.
22. ### Implicit exponential differentiation?

Homework Statement Find an equation of the tangent line to the curve xe^y+ye^x=1 at point (0,1). Homework Equations I do not recall seeing the Implicit Function Theroem before, I even went back in my book (Stewart Calculus 6th) to check. I found this post but it does not help me...
23. ### Schools Engineering and Community College

You need to check with your CC and any universities where you may plan on transferring, and see if they have a transfer agreement. Most of the "engineering core" classes that can be taken at a CC, seem to be math, physics, and chemistry. I am currently taking classes at a CC with a transfer...
24. ### Personal statement critique, honesty appreciated!

It is scary how similar this is to the statement I am planning to write. I too, have a English professor father-in-law, a 4.0, am pursuing an engineering degree, and my successful career has left me wanting to learn more. No military experience though, but thank you for your service. I have...
25. ### Post your spring schedule!

Your crayon still has me surpassed: Calculus 2 (4hrs) Speech (3hrs) Intro to Sociology (3hrs) Ten hours while working 45 is all I can handle, even with 2 gen-ed classes.
26. ### Log function e^(ln12/2)?

Man do I feel like an idiot. Thanks for pointing that out.
27. ### Log function e^(ln12/2)?

Thanks, so... 2e^{\frac{ln12}{2}}=2\sqrt{e^{ln12}}=2\sqrt{12} =4\sqrt{3} and 2\sqrt{e^{ln6}}=2\sqrt{6} giving me: \pi((4\sqrt{3}-\frac{1}{12})-(2\sqrt{6}-\frac{1}{6})) \pi(\frac{1}{12}+4\sqrt{3}-2\sqrt{6}) But that was wrong, and I am unsure how to get the correct answer. How does that...
28. ### Log function e^(ln12/2)?

Sorry, maybe I have made a mistake in my prior work. (this may need to be moved to the calculus section) The problem states: Use the washer method to find the volume of the solid when the region bounded by y=e^(x/2) and y=e^(-x), x=ln6, x=ln12, when the region is revolved around the x-axis...
29. ### Log function e^(ln12/2)?

I have a full equation that looks like this: \pi((2e^{\frac{ln12}{2}}+e^{-12})-(2e^{\frac{ln6}{2}}+e^{-6}))
30. ### Log function e^(ln12/2)?

The problem is e^{(\frac{ln12}{2})} not e^{ln\frac{12}{2}}, that would be e^(ln6)=6