Quiz — correction devoir standard n2.pdf

Question 1 sur 10 20:00

[{"id":3956,"question":"Quelle est la solution de l'équation 2x² - 5x + 2 = 0 ?","option_a":"x = 1 ou x = 2","option_b":"x = 2 ou x = 1\/2","option_c":"x = -1 ou x = -2","option_d":"x = 0 ou x = 5\/2","option_e":"","option_f":"","bonne_reponse":"b","explication":"La solution s'obtient en utilisant la formule des équations du second degré : x = [5 ± √(25 - 16)] \/ 4 = [5 ± 3]\/4, soit x = 2 ou x = 1\/2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"x = 1 ou x = 2\", \"b\": \"x = 2 ou x = 1\/2\", \"c\": \"x = -1 ou x = -2\"","_debug_options_count":4},{"id":3957,"question":"La dérivée de f(x) = x³ - 3x² + 2x est f'(x) = 3x² - 6x + 2.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"La dérivée de x³ est 3x², celle de -3x² est -6x et celle de 2x est 2. Donc f'(x) = 3x² - 6x + 2 est correcte.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":3958,"question":"Quelle est la limite de (x² - 4)\/(x - 2) lorsque x tend vers 2 ?","option_a":"0","option_b":"2","option_c":"4","option_d":"La limite n'existe pas","option_e":"","option_f":"","bonne_reponse":"d","explication":"En factorisant, on obtient (x-2)(x+2)\/(x-2) = x+2 pour x ≠ 2. La limite est donc 4.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"d\", \"options\": {\"a\": \"0\", \"b\": \"2\", \"c\": \"4\", \"d\": \"La limite n'existe pas\"}}","_debug_options_count":4},{"id":3959,"question":"Un triangle est rectangle si et seulement si le carré de l'hypoténuse est égal à la somme des carrés des deux autres côtés.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"C'est l'énoncé du théorème de Pythagore, qui caractérise les triangles rectangles.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":3960,"question":"Quelle est la solution de l'inéquation 3x - 7 \u003E 5x + 1 ?","option_a":"x \u003C -4","option_b":"x \u003E -4","option_c":"x \u003C 4","option_d":"x \u003E 4","option_e":"","option_f":"","bonne_reponse":"a","explication":"En résolvant, on obtient -2x \u003E 8, soit x \u003C -4 après division par -2 (inversion du signe).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"x \u003C -4\", \"b\": \"x \u003E -4\", \"c\": \"x \u003C 4\", \"d\": \"x \u003E 4\"}}","_debug_options_count":4},{"id":3961,"question":"La fonction f(x) = 1\/x est dérivable sur ℝ.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La fonction n'est pas définie en x = 0, donc elle n'est pas dérivable sur tout ℝ.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":3962,"question":"Quelle est la valeur de ∫(2x + 1)dx entre 0 et 2 ?","option_a":"4","option_b":"5","option_c":"6","option_d":"7","option_e":"","option_f":"","bonne_reponse":"c","explication":"L'intégrale vaut [x² + x] entre 0 et 2 = (4 + 2) - (0 + 0) = 6.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"4\", \"b\": \"5\", \"c\": \"6\", \"d\": \"7\"}}","_debug_options_count":4},{"id":3963,"question":"Si deux droites sont parallèles, alors leurs coefficients directeurs sont égaux.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"C'est une propriété fondamentale des droites parallèles dans un repère.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":3964,"question":"Quelle est la solution de l'équation ln(x) = 2 ?","option_a":"x = e","option_b":"x = 2e","option_c":"x = e²","option_d":"x = 1\/e²","option_e":"","option_f":"","bonne_reponse":"c","explication":"En exponentiant les deux côtés, on obtient x = e².","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"x = e\", \"b\": \"x = 2e\", \"c\": \"x = e²\", \"d\": \"x = 1\/e²\"}}","_debug_options_count":4},{"id":3965,"question":"La fonction f(x) = x² est convexe sur ℝ.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"La dérivée seconde f''(x) = 2 est positive, donc la fonction est convexe sur ℝ.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4}]