If (1+ tan A)(1+ tan 4A)= 2, A E ( 0, π/16), THEN A is equal to

(a) π/20  (b) π/30   (c) π/40  (d) π/60

 Explain how???

2 years ago


Answers : (2)


let A +B = pi/4 


or, tanA +tanB = 1-tanAtanB

or, (1+tanA)(1+tanB)=2

 use this result to obtain A+4A = pi/4


A= pi/20

2 years ago








thus 5A=45,


then (a) is the ans.

2 years ago

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