# Algebra 2

posted by Janet

How do I find a and b given the equation ax^2 + bx -4 and a vertex point of (1,-6)?

1. Scott

the vertex is on the axis of symmetry

x = -b / 2a ... 2a = - b

plugging the point into the main equation
... -6 = a(1^2) + b(1) - 4
... -2 = a + b

use the two equations to find a and b

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