HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 101

Keys: |H b bb ‘ ‡ Display: Description: /ºº 1!.2 Shows the current equation in the equation list. º 1!.2-¾ Turns on Equation-entry mode and shows the "¾" cursor at the end of the equation. /ºº 1!.2¾ Deletes the number 25. /ºº 1!.2 Shows the end of edited equation in the equation list.  Leaves Equation mode. Types of Equations The HP 33s works with three types of equations: „ Equalities. The equation contains an "=", and the left side contains more than just a single variable. For example, x2 + y2 = r2 is an equality. „ Assignments. The equation contains an "=", and the left side contains just a single variable. For example, A = 0.5 × b × h is an assignment. „ Expressions. The equation does not contain an "=". For example, x3 + 1 is an expression. When you're calculating with an equation, you might use any type of equation - although the type can affect how it's evaluated. When you're solving a problem for an unknown variable, you'll probably use an equality or assignment. When you're integrating a function, you'll probably use an expression. Evaluating Equations One of the most useful characteristics of equations is their ability to be evaluated - to generate numeric values. This is what enables you to calculate a result from an equation. (It also enables you to solve and integrate equations, as described in chapters 7 and 8). Entering and Evaluating Equations 6-9