# Thread: Derive Mollweide's Formula for Tangent

1. ## Derive Mollweide's Formula for Tangent

Is the law of tangents used at all? Our teacher never introduced it to the class.

Derive (a - b)/(a + b) = tan[(1/2)(A - B)]/tan[(1/2)(A + B)]

Also, who is Mollweide? I know that he was a mathematician but our teacher never told the class anything about this guy.

Thanks

2. Originally Posted by magentarita
Is the law of tangents used at all? Our teacher never introduced it to the class.

Derive (a - b)/(a + b) = tan[(1/2)(A - B)]/tan[(1/2)(A + B)]
what is "a" and "b" supposed to be?

Also, who is Mollweide? I know that he was a mathematician but our teacher never told the class anything about this guy.

Thanks
google is your friend, and a lot of the times, wikipedia too

3. ## no idea...

Our teacher placed that question on the board and walked out of the classroom.