获取了大量K12教育题库数据 json数据显示如下
{ “question_id”: 100, “question_type”: “1”, “question_channel_type”: 1, “channel_type_name”: 单选题， “title”: “
若<math xmlns=“http://www.w3.org/1998/Math/MathML”>α是第四象限角，<math xmlns=“http://www.w3.org/1998/Math/MathML”><mi mathvariant=“normal”>tanα=-512，则<math xmlns=“http://www.w3.org/1998/Math/MathML”><mi mathvariant=“normal”>sinα=()
”, “question_text”: “若<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”>是第四象限角，<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”> ， 则<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”> ”, “options”: { “A”: “<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”>”, “B”: “<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”>”, “C”: “<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”>”, “D”: “<img class=“mathml” src=“https://math.21cnjy.com/MathMLToImage?mml= ” style=“max-width:100%;vertical-align:middle;”>” }, “answer_json”: [ “”, “”, “”, “D” ], “answer_json_text”: null, “answer”: “D”, “answer_text”: “D”, “explanation”: 【答案】根据题意，由于<img data-cke-saved-src=“http://tikupic.21cnjy.com/2b/0c/2ba0ceb45b366219a93be82cee70b97a.png” src=“http://tikupic.21cnjy.com/2b/0c/2ba0ceb45b366219a93be82cee70b97a.png” style=“max-width:100%;”>是第四象限角，<img data-cke-saved-src=“http://tikupic.21cnjy.com/e7/0f/e780f7f5930bf0271c83267bf8ae66c9.png” src=“http://tikupic.21cnjy.com/e7/0f/e780f7f5930bf0271c83267bf8ae66c9.png” style=“max-width:100%;”> ， 可见正弦值为负，余弦值为正，可知分别为<img data-cke-saved-src=“http://tikupic.21cnjy.com/8d/8a/8d88a61c389e87db2d4d80c19f08c51d.png” src=“http://tikupic.21cnjy.com/8d/8a/8d88a61c389e87db2d4d80c19f08c51d.png” style=“max-width:100%;”>然后可知结论是D.”, “knowledge”: { “29409”: { “id”: “29409”, “name”: 同角三角函数之间的基本关系 “ex”: null } }, “t_knowledge”: [ [ { “tid”: “2385”, “name”: 三角函数 } ] ], “knowledge_path”: [ [ { “id”: “2385”, “name”: 三角函数 }, { “id”: “29390”, “name”: 任意角和任意角三角函数 }, { “id”: 29409, “name”: 同角三角函数之间的基本关系 } ] ], “knowledge_info”: { “29409”: { “id”: “29409”, “name”: 同角三角函数之间的基本关系 “ex”: null } }, “category”: { “42299”: { “id”: “42299”, “name”: 同角三角函数的基本关系 } }, “category_path”: [ [ { “id”: “2940”, “name”: 高中数学 }, { “id”: “11735”, “name”: 北师大版 } { “id”: “2946”, “name”: “必修4” }, { “id”: “2960”, “name”: “第三章三角恒等变换” }, { “id”: 42299, “name”: “1同角三角函数的基本关系” } ] ], “parent_id”: 0, “paperid”: “0”, “paper_title”: “”, “xd”: “3”, “chid”: “3”, “exam_type”: “2”, “exam_name”: “常考题”, “difficult_index”: “1”, “difficult_name”: “容易”, “is_objective”: 1, “is_collect”: false, “extra_file”: null, “save_num”: “28”, “new_flag”: false, “is_use”: 0, “paper_source”: null, “link_paper”: 0, “myanswer”: “”, “create_at”: 1432381836, “exit_paper”: [], “explain_sort_need”: 0, “sub_explanation”: null, “access”: true, “list”: null }