HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 74

hp40g+.book Page 10 Friday, December 9, 2005 1:03 AM FCN functions The FCN functions are: Function Root Extremum Slope Signed area Description Select Root to find the root of the current function nearest the cursor. If no root is found, but only an extremum, then the result is labeled EXTR: instead of ROOT:. (The root-finder is also used in the Solve aplet. See also "Interpreting results" on page 7-6.) The cursor is moved to the root value on the x-axis and the resulting x-value is saved in a variable named ROOT. Select Extremum to find the maximum or minimum of the current function nearest the cursor. This displays the coordinate values and moves the cursor to the extremum. The resulting value is saved in a variable named EXTREMUM. Select Slope to find the numeric derivative at the current position of the cursor. The result is saved in a variable named SLOPE. Select Signed area to find the numeric integral. (If there are two or more expressions checkmarked, then you will be asked to choose the second expression from a list that includes the x-axis.) Select a starting point, then move the cursor to selection ending point. The result is saved in a variable named AREA. 3-10 Function aplet