Q: The number of roots of the equation x + 2tanx = π/2 in the interval [0, 2π] is
(A) 1
(B) 2
(C) 3
(D) infinite
Sol. We have x + 2 tanx = π/2 or tan x = π/4 – x/2.
Now the graphs of the curve y = tanx and y = π/4- x/2, in the interval [0, 2π] intersect at three points.
The abscissa of these three points are the roots of the equation.
Hence (C) is the correct answer.
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