Create a vertical 9:16 realistic smartphone photo of a Chinese high school mathematics exam paper printed in black and white on slightly gray paper. The paper is titled "数学试卷" and laid out like an authentic classroom test sheet, with a bold Chinese title, exam instructions, multiple-choice questions, mathematical formulas, algebra expressions, functions, answer options, and at least one small 3D geometry cube diagram. The sheet should look casually photographed by hand, slightly tilted, with uneven classroom lighting, soft shadows, subtle paper creases, realistic paper fibers, minor blur, and mild perspective distortion. Use Chinese text throughout, mixing bold title typography with standard serif body text and clear math notation. Keep the result believable as a photographed exam page rather than a clean digital document. Avoid private student information, real school seals or official logos, answer keys, defamatory or misleading education claims, extra watermarks, unreadable large text blocks, impossible formulas, broken geometry diagrams, excessive blur, cropped title, and low-resolution artifacts.