HP 35s Scientific Calculator - Manual (Page 326)

D-4 More about Solving
Now, solve the equation to find the root:
Example: An Equation with Two Roots.
Find the two roots of the parabolic equation:
x 2 + x – 6 = 0.
Enter the equation as an expression:
Keys: Display: Description:
 Select Equation mode.

X

X
X


Enters the equation.
 

Checksum and length.
 Cancels Equation mode.
Keys: Display: Description:
X

_ Initial guesses for the root.
 
Selects Equation mode; displays
the left end of the equation.
X 


Solves for X; displays the result.
  Final two estimates are the same
to four decimal places.
  f(x) is very small, so the
approximation is a good root.