﻿ SGN Function ---------------------------------------------------------------------------- Action Indicates the sign of a numeric expression. Syntax SGN( numeric-expression) Remarks The SGN function returns a value depending on the sign of its argument. - If numeric-expression > 0, then SGN( numeric-expression) returns 1. - If numeric-expression = 0, then SGN( numeric-expression) returns 0. - If numeric-expression < 0, then SGN( numeric-expression) returns -1. Example The following example calculates and prints the solution for the input quadratic (or second-degree) equation. The program uses the sign of a test expression to determine how to calculate the solution. CONST NoRealSoln=-1, OneSoln=0, TwoSolns=1 ' Input coefficients of quadratic equation. ' ax^2 + bx + c = 0. INPUT;"a = ", A INPUT;", b = ",B INPUT ", c = ",C Test = B^2 - 4 * A * C SELECT CASE SGN(Test) CASE NoRealSoln PRINT "This equation has no real-number solutions." CASE OneSoln PRINT "This equation has one solution. "; PRINT -B-(2 * A) CASE TwoSolns PRINT "This equation has two solutions. "; PRINT (-B + SQR(Test))-(2 * A) " and "; PRINT (-B - SQR(Test))-(2 * A) END SELECT Output a = 3, b = -4, c = 1 This equation has two solutions. 1 and .3333333