Go on: wolframalpha dot com
When page be open in rectangle type:
-4^2+44x-160=0
and click option =
After few seconds you will see graph,and solution .
-4^2+44x-160=0
If you graphed the above equation, would the graph open up or down? How can you tell without graphing it?
3 answers
Thank you very much!!
Since you asked about answering the question without graphing it, let's forget about wolfram. No graph allowed!
However, think of the function:
-4x^2+44x-160
x^2 is always positive. SO, -4x^2 is always negative. So, as x assumes large positive and negative values, -4x^2 becomes a large negative value.
That means that the parabola opens downward.
In general, if the coefficient of x^2 is positive, the parabola opens upward; if negative, it opens downward.
You can play around at wolfram to see that this is so.
However, think of the function:
-4x^2+44x-160
x^2 is always positive. SO, -4x^2 is always negative. So, as x assumes large positive and negative values, -4x^2 becomes a large negative value.
That means that the parabola opens downward.
In general, if the coefficient of x^2 is positive, the parabola opens upward; if negative, it opens downward.
You can play around at wolfram to see that this is so.
1 answer