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  1. C

    Inverse matrix

    Yeah, i multiplied them back and they went ot the identity matrix.
  2. C

    Inverse matrix

    Can someone verify this: |1 -1| = P |-2 1| |-1 -1| For P^-1, i got this. |-2 -1| |-1 -2| My solutions manual, says this is the answer. |-1 -1| My solutions manual has been...
  3. C

    How to factor equations with an exponent of 3

    I'm trying to find the roots of an equation in the form of Ax^3 + Bx^2 + Cx + D I've talked to other people at my school and they say to synthetically divide by a 1, 2, or 3 and see if it goes in evenly then factor the remaining equation. Thanks for everyone's response.
  4. C

    How to factor equations with an exponent of 3

    I know there's a formula somewhere, but how do you factor an equation with an exponent of three. In my solution's manual it says: x^3 - x^2 + 11x - 6 = (x-1)(x-2)(x-3) And i'm just trying to figure out how they got that. Thank you.
  5. C

    How to get a particular solution.

    I have a "Solve the initial value problem" It is: y'' + y = 2cosx - 3sinx I know how to do everything except for get yp. I know it has to be something so when i substitute yp into the left hand side of the equation, i get the right hand side, 2cosx - 3sinx. By this definition i would...
  6. C

    Variation of Parameters

    Hello, I'm trying to understand this concept. Jere's the problem i'm doing. I have to find the general solution for: y'' + 36y = -4xsin(6x) So you then solve for your characteristic equation and get lamda = +/- 6 so y1 = e^-6x and y2 = e^6x You get your matrix for w, w1, and w2. w =...