In which quadrant is sine positive and cosine negative?

In trigonometry, the signs of sine and cosine values depend on the quadrant of the unit circle in which the angle lies.

In Quadrant II, the x-coordinate (which represents cosine values) is negative, while the y-coordinate (which represents sine values) is positive. Therefore, in this quadrant, the sine of an angle is positive because it corresponds to the y-coordinate, while the cosine is negative because it corresponds to the x-coordinate.

This matches the criteria given in the question, where sine must be positive and cosine must be negative. In contrast, other quadrants have different sign combinations: in Quadrant I, both sine and cosine are positive; in Quadrant III, both are negative; and in Quadrant IV, sine is negative while cosine remains positive. Thus, Quadrant II is indeed the correct choice when considering where sine is positive and cosine is negative.