Which of the following quadrants contains the angles for which sine is positive?

The first and second quadrants of the coordinate plane are where the sine of an angle is positive. In the unit circle, angles in the first quadrant range from 0 to 90 degrees (0 to π/2 radians), and in this range, both sine and cosine values are positive. Therefore, sine is positive for all angles in this quadrant.

In the second quadrant, angles range from 90 degrees to 180 degrees (π/2 to π radians). While cosine becomes negative in this quadrant, the sine values remain positive. Thus, any angle measured in degrees or radians that falls within the first or second quadrants will have a positive sine value.

Understanding the quadrants is essential for trigonometric function behavior. As you move to the third quadrant (180 to 270 degrees or π to 3π/2 radians) and the fourth quadrant (270 to 360 degrees or 3π/2 to 2π radians), sine values become negative. This is why the selection of the first and second quadrants as the correct answer is accurate.