determine wether the graph of each parabola opens upward or downward. Dose any one have a clue
y=-1/2 x^2+3
2007-10-21 05:06:55 · 4 answers · asked by sumguy 1 in Science & Mathematics ➔ Mathematics
Yes
Get a piece of graph paper, and graph it out for x = -10 to +10.
Or do it with a spreadsheet application like MS Excel
Also, try the equation y = 1/2 x^2 + 3
By doing both, you should be able to figure out how to answer this question for any equation of the form: y = ax^2 + b ; where a and b are any real numbers between plus and minus infinity
2007-10-21 05:14:33 · answer #1 · answered by Nigel M 6 · 0⤊ 0⤋
If you visualize the parabola the ends either go up or down. So just find out if Y increases or decreases when you move up the X axis.
the term -1/2*X^2 will alway be negative and always decrease as X gets further away from 0. (try a few numbers to see)
So the parabola opens downward.
2007-10-21 12:14:44 · answer #2 · answered by penncomm1 2 · 1⤊ 0⤋
This one opens downward, because the coefficient
of the x² term is negative.
In general, if y = ax²+bx+c the parabola
opens upward if a is positive and downward if
a is negative.
2007-10-21 12:37:41 · answer #3 · answered by steiner1745 7 · 0⤊ 0⤋
If the sign of the x^2 term is positive, then it opens upward. If it is negative, then it opens downward.
2007-10-21 12:20:19 · answer #4 · answered by Richard F 6 · 0⤊ 0⤋