Question

X=tanA-tanB and Y=cotB-CotA.prove that1/X+1/Y=cot (A-B)

Answer 1

hi friend,


1/x=1/tanA-tanB

=1/(1/cotA-1/cotB)

=cotAcotB/cotB-cotA----(1)

1/y=1/cotB-cotA------(2)

by adding (1) and (2)

1/x+1/y=cotAcotB+1/cotB-cotA

=cot(A-B)


I hope this will help u :)

Answer 2

1/x=1/tanA-tanB

=1/(1/cotA-1/cotB)

=cotAcotB/cotB-cotA----> (1)

1/y=1/cotB-cotA----->(2)

by adding (1) and (2)

1/x+1/y=cotAcotB+1/cotB-cotA

=cot(A-B)

Please mark this as the brainliest answer!!:)