HP 40g hp 39g & 40g_user's manual_English_E_pdfbpia5212.pdf - Page 155

Symbolic functions The symbolic functions are used for symbolic manipulations of expressions. The variables can be formal or numeric, but the result is usually in symbolic form (not a number). You will find the symbols for the symbolic functions = and | (where) in the CHARS menu ( CHARS) as well as the MATH menu. = (equals) Sets an equality for an equation. This is not a logical operator and does not store values. (See "Test functions" on page 1020.) expression1 = expression2 ISOLATE Isolates the first occurrence of variable in expression=0 and returns a new expression, where variable=newexpression. The result is a general solution that represents multiple solutions by including the (formal) variables s1 to represent any sign and n1 to represent any integer. ISOLATE(expression,variable) Examples ISOLATE(2*X+8,X) returns -4 ISOLATE(A+B*X/C,X) returns -(A*C/B) LINEAR? Tests whether expression is linear for the specified variable. Returns 0 (false) or 1 (true). LINEAR?(expression,variable) Example LINEAR?((X^2-1)/(X+1),X) returns 0 QUAD Solves quadratic expression=0 for variable and returns a new expression, where variable=newexpression. The result is a general solution that represents both positive and negative solutions by including the formal variable S1 to represent any sign: + or - . QUAD(expression,variable) Example QUAD((X-1)2-7,X) returns (2+s1*5.29150262213)/2 Using mathematical functions 10-19