The parabola y = ax & # 178; + C passes through two points a (2,1), B (- 1, - 5), finds the expression of the parabola, and points out the opening direction and vertex coordinates of the parabola | Math enthusiast | Mathematical art

The parabola y = ax & # 178; + C passes through two points a (2,1), B (- 1, - 5), finds the expression of the parabola, and points out the opening direction and vertex coordinates of the parabola

That is, 1 = 4A + C
-5=a+c
So a = 2, B = - 7
So y = 2x & # 178; - 7
Opening up
Vertex is (0, - 7)

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