If a = tan6 tan 42
and B = cot66 cot 78
then

(a) A = 2B (b)
1
AB
3
=
(c) A = B (d) 3A = 2B.

• a=tan6 tan42
  b=cot66 cot78 can be written as tan24 tan12 bec cot(90-t)=tant;
  tanA tanB = tanC tanD if A+B=C+D; or A+B =C-D or A-B=C+D or A-B=C-D;
  as 42-6=24+12;
  both are equal.
• 11 years agoHelpfull: Yes(34) No(5)
• c) A = B
  
  If A = tan6 tan 42 and B = cot66 cot 78 then,
  
  A/B = 1. So, A =B
• 12 years agoHelpfull: Yes(16) No(7)
• value of tan6tan42=-0.67
  and cot66cot78=-1.005
  so,3A=2B is rd. answer
• 11 years agoHelpfull: Yes(4) No(17)
• We know that tanx*tan(60-x)*tan(60+x)=tan3x
  now A/B=tan6.tan42.tan66.tan78
  
• 9 years agoHelpfull: Yes(1) No(0)
• A=tan6°tan42° and B=cot66°cot78°
  A/B=tan6°tan42°tan66°tan78°
  Using tan(60-x)tanxtan(60+x)=tan3x for x=18° we get
  tan42°tan18°tan78°=tan54°...(1)
  for x=6° we get
  tan54°tan6°tan66°=tan18°...(2)
  Eliminating tan54°between (1) and (2)
  we get
  tan6°tan42°tan66°tan78°=1
  Hence A/B=1.
• 6 years agoHelpfull: Yes(1) No(0)