# Recent content by dmitriylm

1. ### RC circuit formula question

Homework Statement I'm doing a physics lab and have a question about RC circuits. I'm given four formulas: 1a) dQ/dt = -Q/RC 1b) Q = (Qo)e^(-t/RC) 1c) E - RI - Q/C = 0 ---> R(dQ/dt) + Q/C - E = 0 1d) Q(t) = CE[1 - e^(-t/RC)] I am told that 1b is the solution to 1a and 1d is the...
2. ### Mathematic Inductive Proof question

Well (n+1)^2 - 3(n+1) + 2 simplifies to n^2 - n. How do I show that n^2 - n > 0 ?
3. ### Mathematic Inductive Proof question

Homework Statement Give a proof by Mathematical Induction of the following: For all integers n>=3, (n^2 - 3n + 2) is positive. Homework Equations The Attempt at a Solution Hey guys, this is a problem from my discrete mathematics study guide. Here's what I got so far: Proof: n-initial=3...
4. ### How to determine a basis given a set of vectors?

These are column vectors.
5. ### How to determine a basis given a set of vectors?

Homework Statement Let V be the subspace spanned by the following vectors: [ 0]...[ 1 ]...[2] [ 2]...[ 1 ]...[5] [-1]...[3/4]...[0] Determine a basis for V. The Attempt at a Solution I'm not quite sure how to start here. Would placing the vectors in a matrix and deriving its...
6. ### Is {a0 + a1x + a2x^2 + a3x^3 | a0a3 - a1a2 = 0} a subspace of P3?

Thanks a lot for the help!
7. ### Is {a0 + a1x + a2x^2 + a3x^3 | a0a3 - a1a2 = 0} a subspace of P3?

How do I derive the elements of my set from the equation? If I select a0=2, a1=3, a2=4, and a3=6, then these numbers meet the requirements of the equation. Similarly, a0=-2, a1=-3, a2=-4 and a3=-6 would as well. Where do I go from there?
8. ### Is {a0 + a1x + a2x^2 + a3x^3 | a0a3 - a1a2 = 0} a subspace of P3?

Do I need to do anything with the conditions a0a3 – a1a2 = 0?
9. ### Show that all 2x2 matrices with real entries is a vector space under these conditions

Would that be a single column matrix like: [a] [b] [c] [d] ?
10. ### Is {a0 + a1x + a2x^2 + a3x^3 | a0a3 - a1a2 = 0} a subspace of P3?

Homework Statement Is {a0 + a1x + a2x^2 + a3x^3 | a0a3 - a1a2 = 0} a subspace of P3? Why or why not? *The digits should be in subscript. How would I go about answering this?
11. ### Show that all 2x2 matrices with real entries is a vector space under these conditions

I think I've actually got this figured out. I just test two 2x2 matrices of random values under the various axioms and if they pass then under matrix addition and scalar multiplication then it should show that all 2x2 matrices are a real vector space right? What other kind of vector space is...
12. ### Show that all 2x2 matrices with real entries is a vector space under these conditions

Homework Statement Show that all 2 x 2 matrices with real entries: M(2x2) = { a b | a,b,c,d are real numbers} c d | is a vector space under the matrix addition: |a1 b1| + | a2 b2| = |a1+a2 b1+b2| |c1 d1| + | c2 d2| = |c1+c2 d1+d2| and scalar multiplication: r*| a b | = | ra...
13. ### At which points on the x-axis (not at infinity) is the electric potential zero?

Would this be correct: k(-2)/L + k(+3)/L = 0 -2/L + 3/L = 0 -2/L = -3/L Potential is equal to zero at L = -2 and -3?
14. ### At which points on the x-axis (not at infinity) is the electric potential zero?

That's what I was thinking, that zero potential would be directly at the origin. How would I express this in terms of L and Q?
15. ### At which points on the x-axis (not at infinity) is the electric potential zero?

Homework Statement Two point charges -2Q and +3Q are on the x-axis at the origin and at x = L. Find all the points on the x-axis (not at infinity) where the electric potential is zero. Express your answers in terms of L and Q. Homework Equations V= k*Q/r The Attempt at a Solution I...