Mathc initiation/c33bd
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c00d.c |
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/* --------------------------------- */
/* save as c00d.c */
/* --------------------------------- */
#include "x_hfile.h"
#include "fd.h"
/* --------------------------------- */
int main(void)
{
tvalue t;
t.value = 2*PI/4.;
t.min = 0.;
t.max = 2.*PI;
t.step = .05;
CTRL_splot p;
p.xmin = -3;
p.xmax = 3;
p.ymin = -3;
p.ymax = 3;
clrscrn();
printf(" Let C be the curve consisting of all ordered pairs"
" (f(t),g(t)), with :\n\n"
" f : t-> %s \n"
" g : t-> %s\n\n", feq, geq);
printf(" With t = %0.3f, the equation of the tangent is :\n\n"
" y = ((Dg/Df)(t))(x-f(t))+g(t) = ",t.value);
eq_Tan(f,g,DgDf,t.value);
printf("\n\n\n");
printf(" Find PA, the length of the tangent from P to the x axis.\n\n");
printf(" P(%6.3f, %6.3f) P(f(t), g(t)) \n",
f(t.value),g(t.value));
printf(" A(%6.3f, 0.000) A(f(t)-g(t)/(DgDf)(t), 0)\n\n\n",
f(t.value)-g(t.value)/(DgDf)(t.value));
printf(" PA = sqrt( g(t)**2 * (1/(DgDf(t)**2) + 1) )\n"
" = %6.3f\n\n",
sqrt(pow(g(t.value),2)*(1/pow(DgDf(t.value),2)+1)) );
G_TanLx(p,
f,g,DgDf,
t
);
printf(" ... load \"a_main.plt\" ... with gnuplot. \n\n");
stop();
return 0;
}
/* --------------------------------- */
/* --------------------------------- */
Exemple de sortie écran :
Let C be the curve consisting of all ordered pairs (f(t),g(t)), with :
f : t-> (a-b)*cos(t)+b*cos((a-b/b)*t)
g : t-> (a-b)*sin(t)-b*sin((a-b/b)*t)
With t = 1.571, the equation of the tangent is :
y = ((Dg/Df)(t))(x-f(t))+g(t) = -1.000*x +1.000
Find PA, the length of the tangent from P to the x axis.
P(-1.000, 2.000) P(f(t), g(t))
A( 1.000, 0.000) A(f(t)-g(t)/(DgDf)(t), 0)
PA = sqrt( g(t)**2 * (1/(DgDf(t)**2) + 1) )
= 2.828
To see the graph, open the file "a_main.plt" with Gnuplot.
Press return to continue.