Texas Instruments TI-89 User Manual - Page 805

A non-real guess is often necessary to determine a non-real zero. For convergence, a guess might have to be rather close to a zero. cZeros({e^(z_)ìw_,w_ìz_^2}, {w_,z_=1+ i}) ¸ [.149...+4.89...øi 1.588...+1.540...øi] d( ) 2 = key or MATH/Calculus menu d(expression1, var [,order]) ⇒ expression d(list1,var [,order]) ⇒ list d(matrix1,var [,order]) ⇒ matrix Returns the first derivative of expression1 with respect to variable var. expression1 can be a list or a matrix. order, if included, must be an integer. If the order is less than zero, the result will be an antiderivative. d() does not follow the normal evaluation mechanism of fully simplifying its arguments and then applying the function definition to these fully simplified arguments. Instead, d() performs the following steps: d(f(x)ù g(x),x) ¸ ddx(f(x))ø g(x) + ddx(g(x))ø f(x) d(d(x^2ù y^3,x),y) ¸ 6ø yñ ø x d(x^2,x,ë 1) ¸ xò 3 d({x^2,x^3,x^4},x) ¸ {2ø x 3ø xñ 4ø xò } 1. Simplify the second argument only to the extent that it does not lead to a nonvariable. 2. Simplify the first argument only to the extent that it does recall any stored value for the variable determined by step 1. 3. Determine the symbolic derivative of the result of step 2 with respect to the variable from step 1. 4. If the variable from step 1 has a stored value or a value specified by a "with" (|) operator, substitute that value into the result from step 3. data4mat CATALOG/MATH/List menu data4mat data,mat[,row1] [,col1] [,row2] [,col2] Converts data to a matrix. Each argument [,row1][,col1][,row2] [,col2] can be individually omitted. If row1 is omitted the default is 1. If col1 is omitted the default is 1. If row2 is omitted, the default is "max row." If col2 is omitted, the default is "max column." The DATA structure allows empty cells. Rows do not have to be equal size. When data is saved as a matrix, empty cells will be populated with "undef." data4mat d1,m1,1, , ,1 ¸ Done dayOfWk() CATALOG dayOfWk(year,month,day) ⇒ integer dayOfWk(1948,9,6) 2 Returns an integer from 1 to 7, with each integer representing a day of the week. Use dayOfWk() to determine on which day of the week a particular date would occur. Note: May not give accurate results for years Integer values: 1 = Sunday 2 = Monday Appendix A: Functions and Instructions 805