Syntax SIN (angle)
Location QL ROM

This function returns the sine of the given angle (in radians ranging from -PI/2 to PI/2). In a right-angled triangle, the sine is the ratio of the length of the side opposite to the angle, to the length of the hypotenuse. A negative angle indicates that the hypotenuse appears below the base line.


A procedure to draw a sector of a circle with the centre at x,y and radius r.

  • A is the angle between the first straight side of the sector and a vertical line on the screen,
  • B is the angle between the two straight sides.
  • Both angles have to be given in radians, b should be between 0 and 2*PI.
  • Ch specifies the window to be used and cannot be omitted.
100 DEFine PROCedure SECTOR (ch, x, y, r, a, b)
110   LOCal x1, x2, y1, y2
120   x1 = x + r * SIN(a): x2 = x + r *SIN(a + b)
130   y1 = y + r * COS(a): y2 = y + r *COS(a + b)
140   LINE# ch, x1, y1 TO x, y TO x2, y2
150   ARC# ch, x2, y2 TO x1, y1 ,b

SECTOR #1, 50, 50, 10, PI/4, PI/2


SIN (PI)==0 (approximately zero) on all ROMs. This should in fact equal zero - only the Lightning maths package and SMS get this right.


On Minerva v1.96+ SIN with very large values for radian return 0. On other implementations it returns an overflow error. You should therefore check the range of the angle parameter.


See COS, TAN, RAD, ASIN, ACOS, ATAN, DEG. See also SINH. Please also refer to the Mathematics section of the Appendix.