Question

How to know that the trigonometric ratio is of which quadrant?
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Answer 1

$\large\tt\underline{\green{Answer :-}}$

If both x and y are positive, then the point lies in the first quadrant. If x is negative and y is positive, then the point lies in the second quadrant. If both x and y are negative, then the point lies in the third quadrant. If x is positive and y is negative, then the point lies in the fourth quadrant.

Answer 2

Answer:

So the trigonometric ratios are retained in the 1st quadrant. Second is based on angle made with y-axis given as ∠β∠β, in which case the x and y projections are interchanged in magnitude in the 1st quadrant. So the trigonometric ratios are given for complementary angles. It is also noted that ∠α∠αand ∠β∠βare complementary angles.