Subversion Repositories wimsdev

Rev

Rev 16458 | Go to most recent revision | Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
16297 bpr 1
<p>Trinôme \(f(x)=a*x^2+b*x+c) avec \(a \ne 0)&nbsp&nbsp&nbsp&nbsp&nbsp
2
\(\Delta=b^2-4 a c)&nbsp&nbsp&nbsp&nbsp&nbsp
3
\(f(x) = a (x - x_S)^2 + y_S) avec \(x_S=\frac{-b}{2a}) et \(y_S=f(x_S))</p>
4
<table class="wimsborder wimscenter">
5
<tr><td>\(\Delta \lt 0)</td>
6
<td >\(\Delta = 0)</td><td>\(\Delta \gt 0)</td></tr>
7
<tr><td>\(a \gt 0)</td>
8
 <td>\draw{200,200}{
9
xrange -2,8
10
yrange -2,8
11
arrow -2,0,8,0,8, black
12
arrow 0,-2,0,8,8, black
13
dline 0,1,3,1,red
14
dline 3,0,3,1,red
15
text red,  2.9,-0.1 , large, x
16
text red,  3.4,-0.5, small, S
17
 
18
text red,  -1,1.5, large,y
19
text red,  -0.5,1, small, S
20
 
21
plot black, (x-3)^2+1
22
text black,  1.7,4.5, large, f
23
}
24
<table border=1 border="solid">
25
     <tr><td>\(x)</td><td><table border=0 width=150><tr><td align="left">\(-\infty)</td><td align="right">\(+\infty)</td></table></td></tr>
26
     <tr><td>\(f(x))</td><td align="center">+</td></tr>
27
  </table>
28
<br>cas 1
29
 </td>
30
 <td>
31
\draw{200,200}{
32
xrange -2,8
33
yrange -2,8
34
arrow -2,0,8,0,8, black
35
text red,  2.9,-0.1 , large, x
36
text red,  3.4,-0.5, small, S
37
 
38
 
39
plot black, (x-3)^2
40
text black,  1.7,4.5, large, f
41
 
42
}
43
<br><br>
44
  <table border=1 border="solid">
45
     <tr><td>\(x)</td><td><table border=0 width=150><tr><td align="left">\(-\infty)</td><td align="center">\(x_S)</td><td align="right">\(+\infty)</td></tr></table></td></tr>
46
     <tr><td>\(f(x))</td><td align="center"><table border=0 width=150><tr><td align="right">+</td></td><td align="center">0<td align="left">+</td></tr></table></td></tr>
47
  </table>
48
<br>cas 2
49
 </td>
50
 <td>
51
\draw{200,200}{
52
xrange -2,8
53
yrange -5,5
54
arrow -2,0,8,0,8, black
55
arrow 0,-5,0,5,8, black
56
dline 0,-2,3,-2,red
57
dline 3,0,3,-2,red
58
text red,  2.9,1 , large, x
59
text red,  3.4,0.6, small, S
60
 
61
text red,  1.1,-0.1 , large, x
62
text red,  1.6,-0.6, small, 1
63
text red,  4.5,-0.1 , large, x
64
text red,  5,-0.6, small, 2
65
 
66
 
67
text red,  -1,-1.5, large,y
68
text red,  -0.5,-2, small, S
69
 
70
plot black, (x-3)^2-2
71
text black,  1.7,1.5, large, f
72
 
73
}
74
<br><br>
75
  <table border=1 border="solid">
76
     <tr><td>\(x)</td><td><table border=0 width=180><tr><td align="left">\(-\infty)</td><td align="center">\(x_1)</td><td width=20%></td><td align="center">\(x_2)</td><td align="right">\(+\infty)</td></tr></table></td></tr>
77
     <tr><td>\(f(x))</td><td align="center"><table border=0 width=180><tr><td align="right">+</td></td><td align="center" width=20%>0<td align="center">-</td><td align="center">0<td align="left">+</td></tr></table></td></tr>
78
  </table>
79
<br>cas 3
80
 </td></tr>
81
<tr>
82
<td>\(a \lt 0)
83
</td>
84
 <td>
85
\draw{200,200}{
86
xrange -2,8
87
yrange -8,2
88
arrow -2,0,8,0,8, black
89
arrow 0,-8,0,2,8, black
90
dline 0,-1,3,-1,red
91
dline 3,0,3,-1,red
92
text red,  2.9,1 , large, x
93
text red,  3.4,0.6, small, S
94
 
95
text red,  -1,-0.5, large,y
96
text red,  -0.5,-1, small, S
97
 
98
plot black, -(x-3)^2-1
99
text black,  1.7,-4.5, large, f
100
 
101
}<br><br>
102
  <table border=1 border="solid">
103
     <tr><td>\(x)</td><td><table border=0 width=150><tr><td align="left">\(-\infty)</td><td align="right">\(+\infty)</td></table></td></tr>
104
     <tr><td>\(f(x))</td><td align="center">-</td></tr>
105
  </table>
106
<br>cas 4
107
 </td>
108
 <td>
109
\draw{200,200}{
110
xrange -2,8
111
yrange -8,2
112
arrow -2,0,8,0,8, black
113
text red,  2.9,1 , large, x
114
text red,  3.4,0.6, small, S
115
 
116
 
117
plot black, -(x-3)^2
118
text black,  1.7,-4.5, large, f
119
 
120
}
121
<br><br>
122
  <table border=1 border="solid">
123
     <tr><td>\(x)</td><td><table border=0 width=150><tr><td align="left">\(-\infty)</td><td align="center">\(x_S)</td><td align="right">\(+\infty)</td></tr></table></td></tr>
124
     <tr><td>\(f(x))</td><td align="center"><table border=0 width=150><tr><td align="right">-</td></td><td align="center">0<td align="left">-</td></tr></table></td></tr>
125
  </table>
126
<br>cas 5
127
 </td>
128
 <td>
129
\draw{200,200}{
130
xrange -2,8
131
yrange -5,5
132
arrow -2,0,8,0,8, black
133
arrow 0,-5,0,5,8, black
134
dline 0,2,3,2,red
135
dline 3,0,3,2,red
136
text red,  2.9,-0.1, large, x
137
text red,  3.4,-0.6, small, S
138
 
139
text red,  1.6,-0.1 , large, x
140
text red,  2.1,-0.6, small, 2
141
text red,  4,-0.1 , large, x
142
text red,  4.5,-0.6, small, 1
143
 
144
 
145
text red,  -1,2.5, large,y
146
text red,  -0.5,2, small, S
147
 
148
plot black, -(x-3)^2+2
149
text black,  1.7,-1.5, large, f
150
 
151
}
152
<br><br>
153
  <table border=1 border="solid">
154
     <tr><td>\(x)</td><td><table border=0 width=180><tr><td align="left">\(-\infty)</td><td align="center">\(x_2)</td><td width=20%></td><td align="center">\(x_1)</td><td align="right">\(+\infty)</td></tr></table></td></tr>
155
     <tr><td>\(f(x))</td><td align="center"><table border=0 width=180><tr><td align="right">-</td></td><td align="center" width=20%>0<td align="center">+</td><td align="center">0<td align="left">-</td></tr></table></td></tr>
156
  </table>
157
<br>cas 6
158
 </td>
159
</tr>
160
<tr><td>Racines<br>Solutions de<br>\(f(x) = 0)</td><td>Pas de racine.</td><td>\(x_S = x_1 = x_2 = \frac{-b}{2 a})</td><td>\(x_1=\frac{-b-\sqrt{\Delta}}{2 a}) et \(x_2=\frac{-b+\sqrt{\Delta}}{2 a})</td></tr>
161
<tr><td>Factorisation</td><td>Pas de factorisation</td><td>\(f(x) = a (x - x_S)^2)</td><td>\(f(x) = a (x - x_1) (x - x_2))</td></tr>
162
 
163
</table>