Question

bring a three line history about Bios​

Answer 1

Explanation:

tan(2A)=tan[(A+B)+(A-B)]

=tan(A+B)+tan(A-B)/1-tan(A+B)*tan(A-B)

=m+n/1-mn

2B=(A+B)+(B-A), Note B-A=-n

similarly tan2B

=tan[(A+B)-(A-B)]

=m-n/1+mn