Question

if tan A= -2/3 and tan B = 9/4 find tan(A-B)

Answer 1

tan(A-B) = ( tan(A) - tan(B) )/( 1 + tan(A)*tan(B) )


tan(A-B) = ( -2/3 - 9/4 )/( 1 + (-2/3)(9/4) )


tan(A-B) = ( -2/3 - 9/4 )/( 1 - 18/12 )


tan(A-B) = ( -2/3 - 9/4 )/( 1 - 3/2 )


tan(A-B) = ( -35/12 )/( -1/2 )


tan(A-B) = ( -35/12 )*( -2/1 )


tan(A-B) = 35/6