Plotting a function defined by an integral on HP50

[cdecastro]

I have a couple of questions relating to graphing and differentiating functions defined by an integral.

First, when I define

y1(x)=int(1,x, 2*t, t)
y2(x)=int(1,x^2, 2*t, t)

I can perform evaluations.i.e. y1(2) and y2(2), of both functions but am not able to graph y2(x); the grapher reports a "Bad Argument" to the integration method for y2(x).

Additionally if I define y3(x) = diff(y1(x),x), nothing appears when graphed.

While I can certainly perform the differentiation prior to defining y3, I wondered why the grapher cannot deal with this issue. With regard to integration, things are trickier if the integrand does not have an antiderivative expressible in elementary terms. Is there a built-in numerical integration method I can call explicitly?

Thanks in advance for your assistance.

Chris