Values of f(x) may be approaching infinity at the location where the graph changes sign (see figure b, below). This situation is called a pole. Since the SOLVE operation determines that there is a sign change between two neighboring values of x, it returns the possible root. However, the value for f(x) will be relatively large. If the pole occurs at a value of x that is exactly represented with 12 digits, then that value would cause the calculation to halt with an error message.

f (x)

f (x)

x

 

 

x

 

 

 

 

a

b

Special Case: A Discontinuity and a Pole

Example: A Discontinuous Function.

 

Find the root of the equation:

 

 

 

IP(x) = 1.5

 

Enter the equation:

 

 

Keys:

 

Display:

Description:

 

 

Selects Equation mode.

(



)

Enter the equation.

 

 



 





 



 



Checksum and length.

 

 



 

 

 

Cancels Equation mode.

D-6More about Solving