Answers

2015-05-06T21:04:38+05:30
Notice that 39=90-51 and recall the identity \sin(90-x)=\cos(x)

\frac{\sin(39)}{\cos(51)}=\frac{\sin(90-51)}{\cos(51)}=\frac{\cos(51)}{\cos(51)}=\boxed{~1~}
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