One way is to insert a canvas (see menu Insert->Drawing) and use the basic elements and shapes to build the image. I would prefer to import the circuit into Maple as externally created image.

I guess you have to avoid the case k=0

I0 := 1/sqrt(1 - k*cos(t))^3;
(int(I0, t = 0 .. 2*Pi) assuming (-1 < k, k < 0));
(int(I0, t = 0 .. 2*Pi) assuming (0 < k, k <1));

add a step size to seq:

f := unapply(3*x^2 - 2*x^3 - 1.0806746490*x^2*(x - 1)^2 - 0.8118769171*x^2*(x - 1)^3 + 0.4147046974*x^2*(x - 1)^4 + 0.4585681954*x^2*(x - 1)^5, x);

seq(f(x), x = 0 .. 1, 0.1);

Just insert a code edit region into your document, incl. syntax highlighting, parenthesis matching etc.

see ?codeeditregion

There is the Iterator package as well, with alot of functionality regarding partitions. Check it out.

P := Iterator:-Partition(5):

for p in P do
    printf("%d\n", p[1 .. length(P)]);
end do;

Have you updated to Maple 2019.2.1 for better campatibility with Catalina?

Get it here https://de.maplesoft.com/support/downloads/m2019_2update.aspx?L=G

Updating from inside Maple is often slow.

for instance:

i := x;j := p;

`||`(i, j);

cat(i, j);

try

collect(Ty4, exp);

To see what combine is limited to do, check ?combine,exp 

Obviously, your Maple is broken. Contact Maple Customer Support and don't forget to include your Purcase Code you used to activate Maple, because it helps to identify the source of your license. You are not the first one with this error pattern. 

support@maplesoft.com

Play with the options

plot3d(sech(1/2*sqrt(3/5)*(x - 2*t)), x = -10 .. 10, t = -10 .. 10, scaling = constrained, style = patchnogrid, view = [-10 .. 10, -10 .. 10, 0. .. 2.0], tickmarks = [default, default, [0., 1.0, 2.0]]);

Afaik there is no diff tutor for implicit functions. But you could raise printlevel a bit to see what Maple is doing when the command implicitdiff is invoked.

printlevel := 20;
implicitdiff(z*t = cos(z + t), z, t);
printlevel:=1; # reset

You have to place an assumption on a to determine the limit.

V := D__e*(1 - exp(-a*(R - R__e)))^2;

limit(V,R=infinity) assuming a>0;

You should contact Maplesoft support, don't forget to include your 16 digit purchase code.

support@maplesoft.com

You could as well use the library routine for transfer functions

restart;
with(DynamicSystems);
eq1 := 2*diff(y__1(t), t) = -2*y__1(t) - 3*y__2(t) + 2*u__1(t);
eq2 := diff(y__2(t), t) = 4*y__1(t) - 6*y__2(t) + 2*u__1(t) + 4*u__2(t);
T := TransferFunction([eq1, eq2], [u__1(t), u__2(t)], [y__1(t), y__2(t)]):
PrintSystem(T);
 

There is no switch in Maple to do calculations in Degrees, but you could write a tiny procedure:

f := proc(amp, phase) amp*exp(Pi/180*I*phase); end proc;
#Call f with amplitude and degree:
evalf(f(230, 0) - f(20, -30)*f(0.097, 7.2) + f(40, -120)*f(0.097, 7.2));

#If you want to have it in polar coordinates again:
polar(%);

#You still would need to convert the rad to degree:
op(2,%)*180/Pi;