Casio FX-7400G User Manual

Also see for fx-7400G: Programing manual Manual Manual Function guide Manual

Contents

45Differential Calculations Chapter 3This average, which is called thecentral difference, is expressed as:uuuuuTo perform a differential calculationExample To determine the derivative at point x = 3 for the functiony = x3 + 4 x2 + x – 6, when the increase/decrease of x is defined as! x = 1 E – 5Input the function f(x) .AK2(CALC)[1(d/dx )TMd+eTx+T-g,Input point x = a for which you want to determine the derivative.d,Input ! x , which is the increase/decrease of x .bE-f)w• In the function f(x) , only X can be used as a variable in expressions. Other vari-ables (A through Z) are treated as constants, and the value currently assigned tothat variable is applied during the calculation.• Input of !x and the closing parenthesis can be omitted. If you omit ! x , the calcu-lator automatically uses a value for ! x that is appropriate for the value of x = a ,which you specified as the point for which you wanted to determine the deriva-tive.• Discontinuous points or sections with drastic fluctuation can adversely affect pre-cision or even cause an error.• Note that you cannot use differential calculation inside of a differential calculationterm.1 f (a + !x) – f (a) f (a) – f (a – !x)f '(a) = –– ––––––––––––– + –––––––––––––2 !x !xf (a + !x) – f (a – !x)= –––––––––––––––––2!x