Question

tan(a+b)=m
tan(a-b)=n
cot2b=?​

Answer 1

Answer:

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Step-by-step 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