# If 3 tan-1 x + cot-1 x = π, then x equals

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If 3 tan-1 x + cot-1 x = π, then x equals
(a) 0
(b) 1
(c) -1
(d) 1/2

by (-2,838 points)

(b) We have 3 tan-1 x + cot-1 x = π
⇒ 2 tan-1 x + (tan-1 x + cot-1 x) = π

by Basic (24 points)
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