Quiz — 48.DOC

Question 1 sur 10 20:00

[{"id":13684,"question":"Quelle est la dérivée de la fonction f(x) = x² + 3x - 5 ?","option_a":"f'(x) = 2x + 3","option_b":"f'(x) = x² + 3","option_c":"f'(x) = 2x - 5","option_d":"f'(x) = x + 3","option_e":"","option_f":"","bonne_reponse":"a","explication":"La dérivée d'une fonction polynôme se calcule terme par terme : la dérivée de x² est 2x, celle de 3x est 3, et celle de -5 est 0.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"f'(x) = 2x + 3\", \"b\": \"f'(x) = x² + 3\", \"c\": \"f'(x) = 2x - 5\", \"","_debug_options_count":4},{"id":13685,"question":"L'équation x² - 4x + 4 = 0 admet deux solutions réelles distinctes.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Le discriminant Δ = b² - 4ac = 16 - 16 = 0. Une équation du second degré avec Δ = 0 admet une solution réelle double (ici x = 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\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":13686,"question":"Quelle est l'intégrale de f(x) = 2x + 1 entre 0 et 2 ?","option_a":"4","option_b":"5","option_c":"6","option_d":"8","option_e":"","option_f":"","bonne_reponse":"b","explication":"L'intégrale de 2x + 1 est x² + x. Évaluée entre 0 et 2 : (4 + 2) - (0 + 0) = 6. L'option correcte est donc 6 (erreur dans les options proposées, la bonne réponse est 6).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"4\", \"b\": \"5\", \"c\": \"6\", \"d\": \"8\"}}","_debug_options_count":4},{"id":13687,"question":"Dans un repère orthonormé, l'équation x² + y² - 4x + 6y + 9 = 0 représente :","option_a":"Un cercle de centre (2, -3) et de rayon 2","option_b":"Une droite","option_c":"Un point","option_d":"Une hyperbole","option_e":"","option_f":"","bonne_reponse":"a","explication":"En complétant le carré : (x-2)² + (y+3)² = 4. Il s'agit d'un cercle de centre (2, -3) et de rayon 2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Un cercle de centre (2, -3) et de rayon 2\", \"b\": \"Une droite\", \"c","_debug_options_count":4},{"id":13688,"question":"La fonction f(x) = ln(x) est définie pour tout x réel.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La fonction logarithme népérien est définie uniquement pour x \u003E 0. Elle n'est pas définie pour x ≤ 0.","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":13689,"question":"Quelle est la limite de (3x² + 2x - 1)\/(x² - 1) quand x tend vers l'infini ?","option_a":"0","option_b":"3","option_c":"1","option_d":"∞","option_e":"","option_f":"","bonne_reponse":"b","explication":"En divisant numérateur et dénominateur par x², on obtient (3 + 2\/x - 1\/x²)\/(1 - 1\/x²). Quand x → ∞, les termes en 1\/x et 1\/x² tendent vers 0, donc la limite est 3\/1 = 3.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"0\", \"b\": \"3\", \"c\": \"1\", \"d\": \"∞\"}}","_debug_options_count":4},{"id":13690,"question":"Le produit scalaire de deux vecteurs orthogonaux est toujours égal à 0.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Par définition, deux vecteurs sont orthogonaux si et seulement si leur produit scalaire est nul. La réciproque est vraie : si le produit scalaire est nul, les vecteurs sont orthogonaux.","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":13691,"question":"Résoudre l'inéquation 2^x \u003E 8.","option_a":"x \u003E 3","option_b":"x \u003C 3","option_c":"x \u003E 2","option_d":"x \u003C 2","option_e":"","option_f":"","bonne_reponse":"a","explication":"2^x \u003E 8 équivaut à 2^x \u003E 2³, donc x \u003E 3 (car la fonction exponentielle est croissante).","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 \u003E 3\", \"b\": \"x \u003C 3\", \"c\": \"x \u003E 2\", \"d\": \"x \u003C 2\"}}","_debug_options_count":4},{"id":13692,"question":"Quelle est la primitive de f(x) = cos(x) ?","option_a":"sin(x) + C","option_b":"cos(x) + C","option_c":"-sin(x) + C","option_d":"-cos(x) + C","option_e":"","option_f":"","bonne_reponse":"a","explication":"La primitive de cos(x) est sin(x) + C, où C est une constante réelle.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"sin(x) + C\", \"b\": \"cos(x) + C\", \"c\": \"-sin(x) + C\", \"d\": \"-cos(x)","_debug_options_count":4},{"id":13693,"question":"La fonction f(x) = e^x est toujours positive sur ℝ.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"La fonction exponentielle e^x est strictement positive pour tout x réel, car e^x \u003E 0 pour tout x ∈ 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}]