Integral

The Casio Algebra FX2.0 can compute both indefinite and definite integrals.

Integrals from the CAS Screen

Press MENU 9 to access the CAS screen. Press F2 to access the CALC menu, then press 2 to select 2: . This pastes the ( prompt in the entry line of the home screen. Use the syntax (expression,variable). For example, we determine (4x 4 + 3x)dx. In the entry line after the ( prompt, enter:

4 X ^ 4 + 3 X , X ) EXE

Hence, . Note that you need to supply the constant of integration.

For a definite integral, simply add the lower and upper limits of integration. For example, to integrate this function from 1 to 3, enter (4X^4+3X,X,1,3). The answer 998/5 is displayed. For a decimal approximation to an exact answer, press F1 to access the TRNS menu, highlight B:approx and press EXE, then press SHIFT ANS (located above the (-) key) EXE.

Definite Integral from the RUN-MAT Screen

The definite integral also can be computed from either the RUN-MAT screen or from the GRPH-TBL screen.

Press MENU 1 to access the RUN-MAT screen. Press OPTN to view the math options. Press F4 to access the CALC menu. Press 3 to select 3:dx. This pastes the ( prompt in the entry line of the home screen. Use the syntax (expression,variable,lower,upper) where lower (upper) is the lower (upper) limit of integration.

For example, we determine . In the entry line after the ( prompt, type:

SHIFT ( X + 1 ) , X , 1 , 5 ) EXE

Hence, .

To compute a definite integral from the graph screen, first enter the integrand function into the equation editor. We illustrate by computing the above definite integral. Press MENU 3 to access the GRPH-TBL screen. Enter the function as Y1, then press F5 to select DRAW. After the graph is drawn, press F4 to select the G-SLV (graph solve) menu. Press 8 to select 8:dx. The screen displays LOWER, a prompt for the lower limit of integration. Enter the lower limit of integration (here, 1), then press EXE. The screen displays UPPER, a prompt for the upper limit of integration. Enter the upper limit of integration, (here, 5) then press EXE. The area between the curve and the x-axis is shaded and the definite integral is given.