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Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!
Over 15 years teaching at the college level.
NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.
B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook
| User | Date | K | C | P | Comments |
|---|---|---|---|---|---|
| kevin hudson | 01/15/12 | 10 | 10 | 10 | many thanks |
| Miss Susan Wilson | 08/17/11 | 10 | 10 | 10 | Wow!!! You are very fast, as I ..... |
| Andrew Lepkowski | 08/03/11 | 10 | 10 | 10 | |
| Jason | 07/21/11 | 10 | 10 | 10 | Thankyou very much!! |
| Andrew Lepkowski | 07/05/11 | 10 | 10 | 10 | Thank you so much. I was having ..... |
Hello James, The three data points you have slected give the three linear equations for a,b, and c. For the RREF (Reduced Row Echelon Form) algorithm by using "elementary row operations" check these
Hello Jay, For the DE: yy' =(x-1)e^(-y^2), it is separable! ==> y dy/dx = (x-1) e^(-y^2), multiply by e^(y^2) ==> ye^(y^2) dy/dx = (x-1) ==> ye^(y^2) dy = (x-1) dx, now antidifferentiate both
Hello Jenifer, Factor! r^2-5r+6 = (r-3)(r-2) r^2-4 = (r+2)(r-2) So, the ratio is: (r-3)(r-2) ----------, which simplifies to (r+2)(r-2) r-3 ---, for r not equal to 2. r+2 So, you are
Hello Jason, Yes, I see what you mean. Instead, try the following... Notice we can rewrite the DE as: dy/dx = y/x + 2*(x/y)*x^2*cos(x^2), now let u=y/x, so that y=xu and dy/dx=u+x*du/dx, so the
Hello Andrew, Start by letting y(x)=SIGMA(a_n x^n, n=0 to infinity), as usual, then use the power series for e^x, i.e. e^x=SIGMA(x^n/n!,n=0 to infinity)... Can you take it from there? Here are
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