انتگرال نامعین| انتگرال به روش جزء به جزء

New channel donyamath: title sample judged 'pick' (The large majority of uploads are genuine university-level math lectures (calculus, matrices, differential equations), b); passed a second screen for sellers/exam-prep/re-uploads; 0 of 3 sampled transcripts showed teaching, 0 not; titles picked one by one, checked strictly; oEmbed verified.