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