Polynomial Roots Explorer

Drag the root points on the x-axis and watch the polynomial reshape. Change the leading coefficient to flip or stretch.

Polynomial

1.0

Drag the colored dots on the x-axis to move roots.

Properties

Degree--
Roots--
Factored--
y-intercept--
Leading a--
End behavior--

The Math Behind It

Polynomial Basics

  • Factored form: f(x) = a(x-r₁)(x-r₂)...(x-rₙ)
  • Each r is a root (zero) where the graph crosses the x-axis
  • Degree n = number of roots (counting multiplicity)
  • y-intercept = f(0) = a·(-r₁)(-r₂)...(-rₙ)

Leading Coefficient

  • a > 0: right side goes up
  • a < 0: graph flips vertically
  • |a| > 1: graph stretches vertically
  • |a| < 1: graph compresses vertically

End Behavior

  • Even degree, a > 0: both ends go up ↑↑
  • Even degree, a < 0: both ends go down ↓↓
  • Odd degree, a > 0: left down, right up ↓↑
  • Odd degree, a < 0: left up, right down ↑↓

Try This

  • Drag two roots to the same spot — double root (touches but doesn't cross)
  • Make a negative — entire graph flips
  • Try Quintic — see 4 turning points
  • Click Animate — watch leading coefficient sweep