The Three Forms of Quadratic Equations: Vertex Form y a ( x h) 2 k Standard Form Intercept (Factored) Form y ax 2 bx c y a( x p)( x q) What does this form tell us? What does this form tell us? What does this form tell us? “a” UP/DOWN “a” UP/DOWN “a” UP/DOWN VERTICAL STRETCH/SHRINK “a” “a” VERTICAL STRETCH/SHRINK “a” VERTICAL STRETCH/SHRINK Vertex (h, k) You can “see” the vertex in the equation Y-Intercept (0, c) You can “see” the y-intercept in the equation b 2a You MUST find the vertex: x x b 2a then use the x-value to find the y-value x-Intercepts (p, 0) & (q, 0) You can “see” the x-intercepts in the equation You MUST find the vertex: Average the x-intercepts by x pq 2 then use the x-value to find the y-value