I just found out something which I don't understand.

Why am I getting this answer?

solve(a*x = 0, {x});
                                   {x = 0}

When I try some similar expressions I see it behaves differently for equality and inequality.

solve(a*x <= 0, {x});...

I can't solve probably very easy problem. How to plot a filled semicircle which is rotated across one axis by an angle alpha? I came to the solution which I don't consider as the best one (since e.g. it will not work for alpha=Pi/2*(odd integer)) and I believe someone of you will show me a better approach. Thank you in advance.

My solution:

alpha := (1/6)*Pi:
plot3d([x, y, y*tan(alpha)], x = -1 .. 1, y = 0 .. sqrt(1-x^2)*cos(alpha), axes = normal, labels = ["x", "y", "z"...

Can somebody, please, try this command in Maple 16 (or at best Maple 16.02)?

Student[Calculus1][FunctionChart](x*exp(1/x));

In Maple 15 I get the graph in about 1s, however in Maple 16.02 it loads about 20s and it is even not as perfect as is in Maple 15. Furthermore, when I try to evaluate

st:=time():
Student[Calculus1][FunctionChart](x*exp(1/x));
time();

it says that it lasted only 1-2s. There is some problem...

Is it possible to simplify for example the expression

5^2 * 5^(1/2)

to get

5^(5/2) ?

PS: I am sorry if it was asked and answered, I can't find it.

I would like to draw some areas between curves. I tried to use ?plots/implicitplot but I often need to use gridrefine option which consumes so much memory. When I want to draw e.g. the area between f and g:

f := x-> piecewise(x < 5, 2, x-3):
g := x-> piecewise(x < 4, x, 4):

I can do:

p:=plot({f, g}, color...