Question

cosα= -(5/13), π/2<α<π; sin ß= (15/17), π/2<ß<π find Tan(α-ß) tan(a-b)= tana -tanb / 1+ tana tanb

Answer 1

yeah...so find tan a and tan b...( be careful of signs...both should be -ve)put in the formula....then whatever the answer...tan (a-b) must be positive...coz both angles are from 90 to180...and their diff cant be more than 90...so tan(a-b) is +ve