- #1
nk735
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Homework Statement
Show that the matrix [cos(theta), -sin(theta); sin(theta), cos(theta)] is invertible, regardless of the value of theta
Homework Equations
Identity matrix, elementary row operations
The Attempt at a Solution
I have the basic idea as to how to go about this; (let the above matrix = A)
- form an augmented matrix with the identity matrix, eg. [A|I]
- perform row operations (forward and backwards elimination) until matrix looks like [I|A^-1]
However, I'm at a loss as to how to perform these operations with the trigonometric values instead of numbers.
Just a push in the right direction would be greatly appreciated, i'd like to solve this myself