Texas Instruments TI-89 User Manual - Page 837

@list( ) MATH/List menu list(list1) ⇒ list Returns a list containing the differences between consecutive elements in list1. Each element of list1 is subtracted from the next element of list1. The resulting list is always one element shorter than the original list1. @list({20,30,45,70}) ¸ {10,15,25} list4mat() MATH/List menu list4mat(list [, elementsPerRow]) ⇒ matrix Returns a matrix filled row-by-row with the elements from list. elementsPerRow, if included, specifies the number of elements per row. Default is the number of elements in list (one row). If list does not fill the resulting matrix, zeros are added. list4mat({1,2,3}) ¸ [1 2 3] list4mat({1,2,3,4,5},2) ¸ 13 24 5 0 4l n MATH/String menu 4 ln expression ⇒ expression Log(x)4 ln ¸ Causes the input expression to be converted to an expression containing only natural logs (ln). ln(x ) ln(10) ln( ) 2 x key ln(expression1) ⇒ expression ln(list1) ⇒ list Returns the natural logarithm of the argument. For a list, returns the natural logarithms of the elements. ln(2.0) ¸ .693... If complex format mode is REAL: ln({ë 3,1.2,5}) ¸ Error: Non-real result If complex format mode is RECTANGULAR: ln({ë 3,1.2,5}) ¸ {ln(3) + pø i .182... ln(5)} ln(squareMatrix1) ⇒ squareMatrix Returns the matrix natural logarithm of squareMatrix1. This is not the same as calculating the natural logarithm of each element. For information about the calculation method, refer to cos() on. squareMatrix1 must be diagonalizable. The result always contains floating-point numbers. In Radian angle mode and Rectangular complex format mode: ln([1,5,3;4,2,1;6,ë2,1]) ¸ 1..484381......ì+.17.2753...4ø...iøi .009...ì 1.490...øi 1.064...+.623øi ... ...   ë.266...ì 2.083...øi 1.124...+1.790...øi ...  Appendix A: Functions and Instructions 837