# Calculate scalar H number divided by N vector?

Posted 5 months ago
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 Hello. I am trying to calculate the vector X as shown in the attached file. But I don't know what commands to use. Can you give me information about this? Attachments:
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Posted 2 months ago
 Dear Meryem,I must admit I don't understand exactly what you mean.As your expressions in fact aren't simple I decided to do some numerical calculations (see notebook). For this purpose I defined an arbitrary function gg to be inserted for g later on.With several calculations I obtained different solutions for x1 using + or - in H.Note: the two different solution - vectors differ only in the x1-component by a constant. Attachments:
Posted 2 months ago
 Actually, what I want to ask is exactly like this: Here I have changed the sign at the end of the parenthesis (shown in green). I thought the result would also change. But it has not changed. I couldn't understand why. Attachments:
Posted 2 months ago
Posted 2 months ago
 Where is your H?And you write s = 1/4 ( Abs[ Sin[ b s ] +...... So s appears on both sides of the = sign, I wonder that you don't get error messages.
Posted 2 months ago
 In the equation = H, I try to find the vector X. When I change the scalar value "H" here, the result (the vector X) also needs to change. But Mathematica gives the same result. Its stuck on my mind. I wonder where I made a mistake.
Posted 2 months ago
 In the equation = H, I try to find the vector X. When I change the scalar value "H" here, the result (the vector X) also needs to change. But Mathematica gives the same result. Its stuck on my mind. I wonder where I made a mistake.
Posted 2 months ago
 Hmmm. These notebooks don't run on my system. What exactly is your question?
Posted 2 months ago
 Hello. Although I selected the s value differently in these two files, the same result came out. I couldn't understand the reason. I wonder if the results I get are correct. Where do you think I might have made a mistake? Attachments:
Posted 3 months ago
 Attachments:
Posted 5 months ago
 No. There is not an operation like vector / vector. By the way, pressure in general is NOT a scalar, but a Tensor: press = { {pxx, pxy, pxz}, {pyx, pyy, pyz}, {pzx, pzy, pzz} }; and the force experienced by a surface ( given by a vector surf = { sx,sy, sz } is given by force = press.surf Often the off-diagonal elements of press are 0 (this is most likely not the case in vsicous fluids) , and if in addition the diagonal elements are equal = p ( an isotropic medium) the force points in the direction of surf. Then you can write p = Norm[ force ] / Norm[ surf ] press = { {p, 0, 0}, {0, p, 0}, {0, 0, p} }; f1 = press.{1, 1, 1} f2 = press.{2, 3, 4} Norm[f1]/Norm[{1, 1, 1}] Norm[f2]/Norm[{2, 3, 4}] 
Posted 5 months ago
 Can we divide two vectors? Can we divide two vector quantities? For eg., Pressure( a scalar) equals force (a vector) divided by area (a vector).
Posted 5 months ago
 These are exactly the codes I'm looking for. Thank you very much for your help.
Posted 5 months ago
 I think you mean this( < vecN , vecX > = H = prod in this code ) vecN = {a, b, c}; vecX = {x1, x2, x3}; scalar = s; prod = vecN.vecX; lsg=Solve[prod == scalar, x1] // Flatten Then x1 is given as function of x2 and x3. Chose any x2 and x3, calculate x1 and this vector gives your condition. vecX1 = vecX /. lsg vecN.vecX1 
Posted 5 months ago
 First of all, thank you for your reply. There are vectors N and X such that = H. Actually, I'm trying to find the possible values of the X vector. How do I calculate with Mathematica?
Posted 5 months ago