# How can I use manipulate to control many functions with many variables?

I am new to mathematica so i ve trying to solve many equations with different variables using manipulate. So what i have written so far is the following.

Manipulate[
n = 98.5/100;
Q = 8050;
W = 5.2;
H = 6.1;
L = 4.1;
ap = 2*H*L;
A = -Q/W*Log[1 - n];
N = A/ap + ns;
R = ns*L/H;
nd = N - 1;
u = Q/(nd*D*H);
aa = 2*H*L*ns*nd;
Show[{N, R, nd, u, aa}],
{{ns, 2, Row[{"tmimata sti roi ", Text@Style["ns", Italic]}]}, 2, 8, 1, Appearance -> "Labeled"},
{{D, 0.15,Row[{"Diakeno plakwn ", Text@Style["D", Italic]}]}, 0.15, 0.4,0.05, Appearance -> "Labeled"}]


After all of what i have mentioned the results i am getting are all fault. Please, any help is much appreciated.

This gets rid of the errors.

Not a good idea to use variables with UpperCase first letter. In particular, you used N and D which are Mathematica own symbols.

If you want to use a variable with one letter and wanted that be an UpperCase, then good idea to add 0 to it, as in N0, D0, H0.

Also you used Show when there is no graphics. Use Grid for formatting.

Manipulate[

n = 98.5/100;
Q0 = 8050;
W0 = 5.2;
H0 = 6.1;
L0 = 4.1;
ap = 2*H0*L0;
A0 = -Q0/W0*Log[1 - n];
N0 = A0/ap + ns;
R0 = ns*L0/H0;
nd = N0 - 1;
u = Q0/(nd*D0*H0);
aa = 2*H0*L0*ns*nd;

Grid[{{N0, R0, nd, u, aa}}, Frame -> All],

(*control variables below *)
{{ns, 2, Row[{"tmimata sti roi ", Text@Style["ns", Italic]}]}, 2, 8,
1, Appearance -> "Labeled"},

{{D0, 0.15, Row[{"Diakeno plakwn ", Text@Style["D", Italic]}]}, 0.15,
0.4, 0.05, Appearance -> "Labeled"}

]


• Thank you a lot Nasser. Your comments to what i have written so far seem to be very helpful. Also, a big thanks for your kind way to edit and improve my few lines of code. Commented Nov 27, 2017 at 8:20