Question 532173
y = -2x^2 -x + 8
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To find the zeroes, factor or use the quadratic equation:
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-2x^2 -x + 8 = 0
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*[invoke quadratic "x", -2, -1, 8 ]
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To find the vertex...
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First, find the axis is symmetry = -b/2a = -(-1)/(2*(-2)) = -1/4
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Then substitute that value for 'x' and solve for y
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y = -2(-1/4)^2 -(-1/4) + 8
y = -2(1/16) +1/4 + 8
y = -2/16 + 1/4 + 8
y = -1/8 + 1/4 + 8
y = 1/8 + 8
y = 65/8
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vertex = (-1/4, 65/8)
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{{{ graph(500,500,-10,10,-10,10,-2*x^2-x+8) }}}