ℂ
Complex Zeros & Fundamental Theorem
AP Precalculus · Unit 1 Polynomial Functions
Learning Objectives
FTA: degree n polynomial has exactly n roots (complex)
Complex roots come in conjugate pairs
Real zeros are x-intercepts on the graph
Visualize zeros on the complex plane
Key Theorem
Fundamental Theorem of Algebra:
Every non-constant polynomial with complex coefficients has at least one complex root.

Conjugate Root Theorem:
If a+bi is a root, then a−bi is also a root (for real coefficients).
Tags
complex zerosFTAconjugate pairsAP Precalculus
Polynomial Coefficients
Adjust roots to build p(x)
Real Root r₁ -2
Real Root r₂ 3
Complex a (real) 1
Complex b (imag) 2

All Zeros (degree 4)

Polynomial