HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 253

hp40g+.book Page 1 Friday, December 9, 2005 1:03 AM 15 Equation Writer Using CAS in the Equation Writer The Equation Writer enables you to type expressions that you want to simplify, factor, differentiate, integrate, and so on, and then work them through as if on paper. The key on the HOME screen menu bar opens the Equation Writer, and the key closes it. This chapter explains how to write an expression in the Equation Writer using the menus and the keyboard, how to select a subexpression, how to apply CAS functions to an expression or subexpression and how to store values in the Equation Writer variables. Chapter 14 explains all the symbolic calculation functions contained in the various menus, and chapter 16 provides numerous examples showing the use of the Equation Writer. The Equation Writer menu bar The Equation Writer has a number of soft menu keys. TOOL menu Unlike the other soft menu keys, the menu does not give access to CAS commands. Instead, it provides access to a number of utilities to help you work with the Equation Writer. The following table explains each of the utilities on the menu. Equation Writer 15-1