70 POINTS QUESTION ATTACHED (actually attached this time lol)
2 answers:
You might be interested in
If A and B are equal:
Matrix A must be a diagonal matrix: FALSE.
We only know that A and B are equal, so they can both be non-diagonal matrices. Here's a counterexample:
Both matrices must be square: FALSE.
We only know that A and B are equal, so they can both be non-square matrices. The previous counterexample still works
Both matrices must be the same size: TRUE
If A and B are equal, they are literally the same matrix. So, in particular, they also share the size.
For any value of i, j; aij = bij: TRUE
Assuming that there was a small typo in the question, this is also true: two matrices are equal if the correspondent entries are the same.
Answer:
The Pythagorean identity states that
Using that we can rewrite the left denominator as:
Which can be factored as
The numerator we can expand as:
On the right hand side, let's multply numerator and denominator with (1 - sin t):
The total formula then becomes:
There you go... left and right are equal.