tanB=1/2
inverse the tan
B=tan^-1(1/2)
B=26'33'54.18'
tan(A+B)=[tex]\frac{tanA+tanB}{1-tanAtanB}[/tex]
3=[tex]\frac{tanA+tan26'33'54.18'}{1-tanAtan26'33'54.18'}[/tex]
3=[tex]\frac{tanA+(1/2)}{1-(1/2)tanA}
Multiply both sides by 1-1/2tanA
3-3/2tanA=tanA+1/2
Multiply both sides by 2 to make it easier
6-3tanA=2tanA+1
5=5tanA
1=tanA
inverse the tan
tan^-1(1)=A
A=45 degrees.
Hope this helps =)