Step 1 :Given the scalar function \(f(x, y, z) = e^{xyz} + \arccos(x+y) - z^2\) and the vector function \(\mathbf{r}(t) = \langle t^2, -t^2, -3t \rangle\) with \(0 \leq t \leq \frac{1}{2}\).
Step 2 :The Fundamental Theorem of Line Integrals states that if a vector field F is the gradient of a scalar function f, then the line integral of F along a curve C from point A to point B is equal to f(B) - f(A).
Step 3 :In this case, the vector field F is the gradient of the scalar function f. The curve C is parameterized by the vector function r(t).
Step 4 :The points A and B are the initial and final points of the curve C, which are r(0) and r(1/2), respectively. We can substitute the coordinates of points A and B into the scalar function f to compute f(B) - f(A).
Step 5 :Substituting the coordinates of points A and B into the scalar function f, we get \(f(A) = f(0, 0, 0)\) and \(f(B) = f(0.25, -0.25, -1.5)\).
Step 6 :Computing the difference \(f(B) - f(A)\), we get the value of the line integral as -2.1517148596921745.
Step 7 :Final Answer: The value of the line integral is \(\boxed{-2.1517148596921745}\).