Solving Linear Math Inverse Homework: A=4e^4txsin(4t)

  • Thread starter Thread starter ~Sam~
  • Start date Start date
  • Tags Tags
    Inverse Linear
AI Thread Summary
The discussion revolves around finding the inverse of a 2x2 matrix defined by A=4e^4t x sin(4t) and related terms. Participants mention using the determinant equation 1/(ad-bc) to solve for the inverse but express confusion over simplifying the multiplication due to the complex variables involved. There is a request for clarification on the determinant expression and the steps taken to arrive at a solution. Additionally, the use of the trigonometric identity sin^2(t) + cos^2(t) = 1 is suggested to aid in simplification. The conversation emphasizes the need for clearer steps in the calculation process.
~Sam~
Messages
70
Reaction score
0

Homework Statement


pt)
If A=
4e^4t x sin(4t) 4e^2t x cos(4t)
-3e^4t x cos(4t) 3e^2t x sin(4t)

Then A inverse is?

x= times
^=power

sorry for bad format

Homework Equations



Since it's 2x2 I know you can use the determinant equation 1/(ad-bc) ..etc

The Attempt at a Solution



Because of the weird variables I'm not sure how to simplify the multiplication when doing the determination equation.
 
Physics news on Phys.org
I assume you've have managed to get an answer that is correct, and are just looking for help simplifying?

Care to show us what you got? (Or, maybe just the expression you got for the determinant?)
 
Hurkyl said:
I assume you've have managed to get an answer that is correct, and are just looking for help simplifying?

Care to show us what you got? (Or, maybe just the expression you got for the determinant?)

well the answer i got was long..i just subbed the variables in the equation.
 
?? You "subbed the variables" into what equation?
 
use sin^2(t) +cos^2(t) = 1
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Essentially I just have this problem that I'm stuck on, on a sheet about complex numbers: Show that, for ##|r|<1,## $$1+r\cos(x)+r^2\cos(2x)+r^3\cos(3x)...=\frac{1-r\cos(x)}{1-2r\cos(x)+r^2}$$ My first thought was to express it as a geometric series, where the real part of the sum of the series would be the series you see above: $$1+re^{ix}+r^2e^{2ix}+r^3e^{3ix}...$$ The sum of this series is just: $$\frac{(re^{ix})^n-1}{re^{ix} - 1}$$ I'm having some trouble trying to figure out what to...
Back
Top