Exam Strategy

Readiness Check

You are ready when you can:

• Build A from basis images (4.13.A.2).
• Write/use rotation matrix (4.13.A.3).
• Interpret |det(A)| as area dilation (4.13.A.4).
• Compose transformations via matrix product (4.13.B.2).
• Find L^-1 with A^-1 (4.13.C.2).
• Identify/describe from graphs (2.A, 3.A).

Course vs AP Exam

Course scope only (Unit 4 additional topic; not on the AP Exam). These skills still matter for Unit 4 coursework and readiness for 4.14.

Tactics (course assessments)

1. Record images of (1,0) and (0,1) as columns of A. 2. For rotation, use [[cos,-sin],[sin,cos]]. 3. Compute |det| for dilation magnitude. 4. Composition: multiply matrices in correct order. 5. Inverse: use A^-1 when det!=0; verify composition undo.

Common Traps

• Swapped rotation signs.
• Wrong composition order.
• Using det without absolute value for area magnitude.

Quick Checklist

• [ ] Basis images identified
• [ ] Matrix A built correctly
• [ ] |det| interpreted when needed
• [ ] Composition order correct
• [ ] Inverse verified when applicable