SGN Function Programming Example
The following program 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
Sample Output
This equation has two solutions: .6666667 -.25