What is the vertex of a parabola having the equation y = –2(x – 5)2 + 7? Which direction does the parabola open?
1 answer:
That's vertex form for a parabola and we read off vertex (p,q) as
Answer: Vertex (5,7)
The negative <em>a</em> tells us this is a downward opening parabola (upside down from the usual . I remember CUP - Concave Up Positive; here <em>a </em>is negative so not a cup, instead concave <em>down.</em> The same rule applies to second derivatives in calculus so memorize it now and use it later.
Answer: downward
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Answer: y = (-2/5)x - 7
This is the same as writing
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Explanation:
Any linear equation is of the form y = mx+b, known as slope-intercept form
m = slope
b = y intercept
We'll replace m with -2/5 and replace b with -7 to get y = (-2/5)x + (-7) which simplifies to y = (-2/5)x - 7