TI-89: definite integral; easy way to enter?

Question

I am entering definite integrals the hard way on my ti-89 (I'm entering the funtion twice (with two values)). What is an easier way to do this please?

thank you! this is what I needed: x , a , b

Answer 1

I don't know how you are currently doing it but there's an integral symbol over the 7. Press the yellow "2nd" button then 7 to get the integral symbol.

The correct format of typing the definite integral is:

⌠( f , x , a , b)
⌡

Where f is your function, x is the variable you are integrating with respect to, a is the lower limit and b is the upper limit.

If you wanted to find the integral of f(x) = x^2 from 0 to 2 you would type:
⌠(x^2, x, 0, 2)
⌡

If you ever forget the format, press the catalog button. Find the integral symbol in the list. Move the triangle in the window so it is next to the integral symbol. Then check the bottom left of the window. It gives a brief description of the correct format.

expr, var [,low,up]

expr is your expression ( function)
var is the variable you are integrating with respect to.
low is the lower bound
up is the upper bound
The brackets [ ] mean this part is optional. If you don't put the bounds it uses 0 and 1 as the bounds.