Grade 11TrigonometryQ1)If in a triangle, a= 6, b= 3 and cos(A-B)=4/5, then find its area? Q2)Let the angles of a A,B,C of a triangle ABC be in A.P.and let b:c=under root(3):under root(2).Find the angle A? Devesh Lall 14 Years agoGrade 11
Arjun Blouria14 Years agocos(A-B)=4/5 therefore, 1-tan2(A-B)/2 = 4/5 1+tan2(A-B)/2 By componendo dividendo, 2tan2(A-B) = 5-4 2 5+4