Free · Worked example · 14 problems · Answer key · US Letter
How to do it
The vertex is at x = −b ÷ 2a. Put that x back in to find y.
y=x2+2x+9vertex: (−1,8) 2(1)−2=−1x = −b ÷ 2a y=(−1)2+2(−1)+9=8put x = −1 back in vertex (−1,8);axis of symmetry x=−1 Example problems
- y=−2x2+4x+8vertex:
- y=3x2+30x+87vertex:
- y=−2x2+4x−4vertex:
- y=−2x2+8x−18vertex:
Quadratic and polynomial functions
- Vertex form of a quadratic
- Finding the vertex from standard form
- The discriminant
- Quadratic equations with complex roots
- Polynomial long division
- Synthetic division
- The remainder theorem
- The factor theorem
- The rational root theorem