Derivative


The Casio Algebra FX2.0 can compute the derivative of a function and the derivative evaluated at a point.

Derivative of a Function, CAS Screen

Press MENU 9 to access the CAS screen. Press F2 to access the CALC menu. Press 1 to select 1:diff. This pastes the diff( prompt in the entry line of the CAS screen. Use the syntax

diff(expression,variable)

For example, differentiate 4x 4 + 3x with respect to x. In the entry line after the diff( prompt, type:

4 X ^ 4 + 3 X , X ) EXE

Hence, (4x 4 + 3x)' = 16x 3 + 3.

While in the CAS screen, one may obtain higher derivatives and evaluate derivatives. For a higher derivative, use the syntax diff(expression, variable, n) where n is the order of the derivative. For example, let’s find the second derivative of y = 3x 3 - x + 7. In the entry line, after the diff( prompt, type

3 X ^ 3 - X + 7 , X , 2 ) EXE

Hence, (3x 3 - x + 7)" = 18x.

To evaluate an nth order derivative at x =a, use the syntax diff(expression, variable, n, a). For example, to calculate the second derivative of y = 3x 3 - x + 7 at x = 4, enter diff(3X^3-X+7,X,2,4). To find the derivative of 4x 4 + 3x at x = 2, enter diff(4X^4+3,X,1,2).

Derivative of a Function at a Point, RUN-MAT Screen

Press MENU 1 to access the RUN-MAT screen, then press OPTN to see the MAT options. Press F4 to access the CALC menu, then either press 1 or EXE to select 1:d/dx. This pastes the d/dx( prompt in the entry line of the home screen. Use the syntax

d/dx(expression,a)

where a is the number at which you want the derivative evaluated.

For example, differentiate and evaluate the derivative at x = 0. After the d/dx( prompt in the entry line, type

2nd ( X + 1 ) , 0 ) EXE

The derivative of at x = 0 is 0.5.