1. {'id': 'u06-l01', 'number': 1, 'title': 'Reciprocal, Quotient & Pythagorean Identities', 'family': 'identities', 'week': 16, 'unit': 6, 'unit_title': 'Trigonometric Identities & Equations', 'essential': 'How can equivalent forms, identities, algebraic reasoning, and interval analysis simplify expressions and solve trigonometric equations?', 'project': 'Identity Proof Portfolio & Equation Audit'}
Rewrite tan x using sine and cosine.