Recent content by jtruth914

  1. J

    Equivalent Conditions for Nonsingularity (Matrices)

    The book uses that notation to refer to the column.
  2. J

    Equivalent Conditions for Nonsingularity (Matrices)

    I think a1 is referring to the entries in matrix A.
  3. J

    Equivalent Conditions for Nonsingularity (Matrices)

    True or False. If true explain or prove answer, and if false give an example to show the statement is not always true. 1. If A is a 4x4 matrix and a1+a2=a3+2a4, then A must be singular. 2. If A is row equivalent to both B and C, then A is row equivalent to B+C. My Work: 1. I say it's...
  4. J

    How Does Matrix Transposition Affect the Product A^T A?

    Let B=A^{T}A. Show that b_{ij}=a^{T}_{i}a_{j}. I have no idea how to approach this problem.
  5. J

    How Can You Solve the Linear System Ax=b with Given Vectors a1 and a3?

    Let Ax = b be a linear system whose augmented matrix (A|b) has reduced row echelon form 1 2 0 3 1 ||-2 0 0 1 2 4 || 5 0 0 0 0 0 || 0 0 0 0 0 0 || 0a) Find all solutions to the system b)If a1= (1,1,3,4) and a3=...
  6. J

    Solving Laplace Transform for t-tU(t-1)

    I still don't understand where -[1/4 +1/2(t-1) -1/4 e^-2(t-1)] U(t-1) comes from. The answer is y= 1/4 + 1/2t +1/4 e^-2t -[1/4 +1/2(t-1) -1/4 e^-2(t-1)] U(t-1). Where does the second part of the answer come from.
  7. J

    Solving Laplace Transform for t-tU(t-1)

    I attached the problem as a word document. I'm stuck trying to determine the laplace transform for t-tU(t-1). I know I'm supposed to work with 1/s^2(s+2) and solve for A, B,C. I got B=1/2, A=-1/4, and C=1/4 when 1=(As+B)(s+2)+Cs^2. The answer to the problem is y= 1/4 + 1/2t +1/4 e^-2t -[1/4...
  8. J

    How to Simplify and Solve the Inverse Laplace Transform of 1/(s^2+s-20)?

    Having difficulty with L-1 {1/(s^2+s-20)}: Should I make it L-1 {1/(s+5)(s-4)}? I'm stuck.
  9. J

    Second order differential equation

    Find a solution to the following second order differential equation xy'+y=1/y^2 My Attempt: P= y'= dy/dx x dy/dx + y = 1/y^2 dy/dx + y/x = 1/xy^2 Integrating Factor = e^∫1/x dx = e^lnx y e^lnx=∫ (e^lnx)(1/xy^2) dx
  10. J

    Determine Activation Energy from rate?

    No he didn't. I assumed it was a zeroth order reaction where k=rate. Even though he didn't specify that. That's what confused me.
  11. J

    Determine Activation Energy from rate?

    On my test the professor gave us the rate, parameters of A, and temperature of 298K. We were asked to find the activation energy. I know that the Arrhenius equation is LnK= LnA-Ea/RT. However, he did not give us the rate constant "K" instead he gave us the rate. How do you determine activation...
  12. J

    Solving Partial Pressures for H2 & Cl2 given K & PHCl

    a) Determine K at 298K for the reaction H2(g) + Cl2(g) <---> 2HCl(g) b) The equilibrium partial pressure of HCl is 1 bar. Determine the equilibrium partial pressures of H2 and Cl2. This question was on my test. I got K= 3.2 x 10^-34 using dG*=-RTlnK when dG=0 at equilibrium. I'm having...
  13. J

    How Do Stoichiometric Coefficients Affect Gibbs Free Energy Calculations?

    Hey, I had the same concern. They are both right; it depends on the stoichiometry. The professor would have to specify which one he is looking for like he did last time.
  14. J

    P.Chem: Rate of chemical reactions; Half-life

    A second- order reaction of the type A + B -->P was carried out in a solution that was initially 0.075 mol dm^-3 in A and 0.050 mol dm^-3 in B. After 1.0 h the concentration of A had fallen to 0.020 mol dm^-3. a) Calculate the Rate constant. b) Solve for the half- life of each of the reactants...
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