no of solution of the equation x plus 2 tanx = pie/2 in the interval of 0 to 2 pie

Answer: 3

Step-by-step solution

Step 1: Rearrange into two intersecting functions

We can rewrite the given equation x+2tan⁡x=π2x + 2\tan x = \frac{\pi}{2} by isolating the trigonometric function tan⁡x\tan x. Subtracting xx from both sides and dividing by 22 gives tan⁡x=12(π2−x)=π−2x4\tan x = \frac{1}{2}\left(\frac{\pi}{2} - x\right) = \frac{\pi - 2x}{4}. Thus, the solutions correspond to the points of intersection between the curve y=tan⁡xy = \tan x and the line y=π−2x4y = \frac{\pi - 2x}{4} on the interval [0,2π][0, 2\pi].

Step 2: Analyze the functions on the sub-intervals

The tangent function tan⁡x\tan x has vertical asymptotes at x=π2x = \frac{\pi}{2} and x=3π2x = \frac{3\pi}{2}. Therefore, the domain [0,2π][0, 2\pi] splits naturally into three continuous intervals: [0,π2)[0, \frac{\pi}{2}), (π2,3π2)(\frac{\pi}{2}, \frac{3\pi}{2}), and (3π2,2π](\frac{3\pi}{2}, 2\pi]. On each interval, y1=tan⁡xy_1 = \tan x is strictly increasing, while the line y2=π4−x2y_2 = \frac{\pi}{4} - \frac{x}{2} is strictly decreasing.

Step 3: Check intersections in each interval

In [0,π2)[0, \frac{\pi}{2}), y1y_1 increases from 00 to ∞\infty while y2y_2 decreases from π4≈0.785\frac{\pi}{4} \approx 0.785 to 00, yielding exactly 11 root. In (π2,3π2)(\frac{\pi}{2}, \frac{3\pi}{2}), y1y_1 increases continuously from −∞-\infty to ∞\infty, so it intersects the line exactly once. In (3π2,2π](\frac{3\pi}{2}, 2\pi], y1y_1 increases from −∞-\infty to 00 while y2y_2 takes values in [−3π4,−π2)≈[−2.36,−1.57][-\frac{3\pi}{4}, -\frac{\pi}{2}) \approx [-2.36, -1.57]; since y1(2π)=0>y2(2π)=−3π4y_1(2\pi) = 0 > y_2(2\pi) = -\frac{3\pi}{4}, the Intermediate Value Theorem ensures exactly 11 intersection here as well.

Step 4: Sum the total number of solutions

Since there is exactly 11 solution in each of the 33 disjoint sub-intervals, the equation x+2tan⁡x=π2x + 2\tan x = \frac{\pi}{2} has a total of 33 solutions in the interval [0,2π][0, 2\pi].

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