Answer:
tan(α) = 1/tan(90°-α)
Step-by-step explanation:
The tangent of one is the reciprocal of the tangent of the other.
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In a right triangle, ...
tan = opposite/adjacent
For the two complementary acute angles in such a triangle, opposite and adjacent are swapped. That is the tangent of one is the inverse of the tangent of the other. (That inverse is also known as the cotangent.)
tan(α) = cot(90°-α) = 1/tan(90°-α)
