integral of e^(x^2)

[darkside312]

how do i get the integral of e^x^2 on my ti-89 titanium?
whenever i put it in, it just gives me the integral back

if there is no regular solution to this, is there a program i can get to do it?
if not...can somebody make me a program? one that can do things with integrals that have exponents with exponents(not necessarily with e^x or some form of it)?

[mumbles]

you cannot integrate this without it being multiplied by a factor of 2X. this is similar to the idea of putting a 1/2 out front to get a 2 inside of the integral. I do not think your allowed to multiply by a variable like that but it would have to be present for the integral to work.
Hope that helps.

[mumbles]

another example of this is if you wanted to integrate sin(x^2). it would need to be intg[sin(x^2)*x] dx. or for example if it were sin(4x) you would need a 1/4 in front of the integral to put a 4 inside of it. 1/4 intg[sin(4x)*4]dx

[BlainUSM]

A closed-form expression does not exist for the integral e^(x^2) (and many other related integrals). However, you may use "nInt" to approximate the integral of e^(x^2) over any closed interval [a, b]. For example, type

"nInt( e^(x^2), x, 0, 1)"


to integrate (numerically) over [0, 1]. Your output should be


1.462652 (I rounded the rightmost digit.)


The command nInt may also be used (with caution) to integrate over other types of intervals. For example


"nInt( 1/sqrt(2*pi)e^(-(x^2)/2), x, -inf, inf)”,


will give the TI-89’s approximation of the total area under a standard normal curve (where "inf" is the symbol for infinity (accessed by pushing the green key and then the “CATALOG” key.) Your output should be close to 1.

For most well-behaved functions the approximation of the integral should be accurate to six or more significant digits, as indicated in the TI-89 user manual.