11.12. Sign Function
The sign function (also known as the signum function) defines y as a function with range values of 0, 1, -1 and |x| (the absolute value of x). It is a piece-wise function as shown below:
The function implies that the value of any negative number is always -1, the sign of 0 is 0, and the value of any positive number is 1. The sign of any complex number is the result when x is divided by its absolute value, e.g. sign(2i) = i.
To find a value using the sign function, type "sgn" and enter the argument. If the argument is longer than one term, enclose it in parentheses.
Examples
Find the sign of each number below.
1) sign (-4)
2) sign (12 - 3 + 4)
3) sign (5 - 4^2)
4) sign (0)
5) sign (3i + 5)
Calculator solutions
Switch to the a-z keyboard and type in "sgn" to calculate the signum of a number. Enter the argument in parentheses.
Enter each expression with one expression per line.
1) sgn-4. Hit enter to go to a new line.
2) sgn(12 - 3 + 4). Hit enter.
3) sgn(5 - 4^2). Hit enter.
4) sgn(0). Hit enter.
5) sgn(3i + 5)
To find a value using the sign function, type "sgn" and enter the argument. If the argument is longer than one term, enclose it in parentheses.
Examples
Find the sign of each number below.
1) sign (-4)
2) sign (12 - 3 + 4)
3) sign (5 - 4^2)
4) sign (0)
5) sign (3i + 5)
Calculator solutions
Switch to the a-z keyboard and type in "sgn" to calculate the signum of a number. Enter the argument in parentheses.
Enter each expression with one expression per line.
1) sgn-4. Hit enter to go to a new line.
2) sgn(12 - 3 + 4). Hit enter.
3) sgn(5 - 4^2). Hit enter.
4) sgn(0). Hit enter.
5) sgn(3i + 5)