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SSC CPO Tier 1 Exam 10 Dec 2025 Shift 1

Section: Quantitative Aptitude

Question : 137 of 200

Marks: +1, -0

If tanx=cot(2x-15°) find x

Solution:

Concept:

The tangent and cotangent of an angle are complementary:

\cot \theta = \tan(90° - \theta)

Explanation:

Given

\tan x = \cot(2x - 15°)

Rewrite the cotangent as tangent:

\cot(2x - 15°) = \tan[90° - (2x - 15°)] = \tan(105° - 2x)

Now the equation becomes

\tan x = \tan(105° - 2x)

Since the tangent function is one‑to‑one in the principal range, we equate the angles:

x = 105° - 2x

Solve:

x + 2x = 105°

→

3x = 105°

→

x = 35°

Answer:

x = 35°

(Option B).

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