Somehow the sine is multiplied by -1 in the asy files.
In the text 14_Line_Integral_Intro.tex you have:
134: {Find the area under the surface $f(x,y) =\cos(x)+\sin(y)+2$ over the curve $C$, which is the segment of the line $y=2x+1$ on $-1\leq x\leq 1$, as shown in Figure \ref{fig:linescalarfield2}.
138: We find the values of $f$ over $C$ as $f(x,y) = f(t,2t+1) = \cos(t)+\sin(2t+1) + 2$.
while in the figures figlinescalarfield2_3D.asy and figlinescalarfield2b_3D.asy you have
4: // The surface is z=cos(x)+sin(y)+2; the path is the line
38: //Draw the surface z=cos(x)+sin(y)=2
40: return (t.x,t.y,-sin(t.y)+cos(t.x)+2);
48: triple g(real t) {return (t,2*t+1,-sin(2t+1)+cos(t)+2);}
and
4: // The surface is z=cos(x)+sin(y)=2; the path is the line
37://Draw the surface z=cos(x)+sin(y)=2
39: return (t.x,2*t.x+1,t.y*(-sin(t.x*2+1)+cos(t.x)+2));
47:triple g(real t) {return (t,2*t+1,-sin(2t+1)+cos(t)+2);}
Somehow the sine is multiplied by -1 in the asy files.
In the text 14_Line_Integral_Intro.tex you have:
134:
{Find the area under the surface $f(x,y) =\cos(x)+\sin(y)+2$ over the curve $C$, which is the segment of the line $y=2x+1$ on $-1\leq x\leq 1$, as shown in Figure \ref{fig:linescalarfield2}.138:
We find the values of $f$ over $C$ as $f(x,y) = f(t,2t+1) = \cos(t)+\sin(2t+1) + 2$.while in the figures figlinescalarfield2_3D.asy and figlinescalarfield2b_3D.asy you have
4:
// The surface is z=cos(x)+sin(y)+2; the path is the line38:
//Draw the surface z=cos(x)+sin(y)=240:
return (t.x,t.y,-sin(t.y)+cos(t.x)+2);48:
triple g(real t) {return (t,2*t+1,-sin(2t+1)+cos(t)+2);}and
4:
// The surface is z=cos(x)+sin(y)=2; the path is the line37:
//Draw the surface z=cos(x)+sin(y)=239:
return (t.x,2*t.x+1,t.y*(-sin(t.x*2+1)+cos(t.x)+2));47:
triple g(real t) {return (t,2*t+1,-sin(2t+1)+cos(t)+2);}