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

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:

- and +.png

s=+1....nb

s=-1....nb

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.

In the equation <N, X> = 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.

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:

s=+1....nb

s=-1....nb

These are exactly the codes I'm looking for. Thank you very much for your help.

Yes:

h.dolhaine@gmx.de

1) N is a Mathematica-Symbol. Look it up in the Help-Section. You shouldn't use N, try vN or so.

2) Your "N" clearly is a vector of dimension 3. But your H is a scalar. Tell me , why should

scalar / vector

an operation that is - at least - not well (if not far from ) defined be a vector? Did you mean N / H ?