Mathematics
Gabbyman
2016-04-29 01:23:27
Find the gradients of the lines that pass through the point (1,7) and are tangent to the parabola y = (2−x)(1+3x).
ANSWERS
KatieLuiker
2016-04-29 03:21:12

y=(2-x) (1+3x) This is vertical. and that should be 4x=1

cocopuffs
2016-04-29 03:22:27

[latex]y = (2-x)(1+3x)[/latex] [latex] = 2 + 6x - x - 3x^{2}[/latex] [latex] = 2 + 5x - 3x^{2}[/latex] [latex]frac{dy}{dx} = m = 5 - 6x[/latex] At x = 1: [latex]frac{dy}{dx} = m = 5 - 6 = -1[/latex] [latex]y - 7 = -(x - 1)[/latex] [latex]y = -x + 8[/latex] [latex] herefore y = 8 - x[/latex]

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