y=16x^2+190x+0

Question

my daughter has to graph a parabola however when inputting the equation, it appears to be almost a straight line and not the vertex as seen in examples.  help.

 

 

Answer 1

Plotting y=16x^2+190x+0

 

The parabola is "extreme" which is why you are seeing a "line". If you choose "x" values near the vertex it will look parabolic. The vertex is located close to x = 6.  Try values around 6.

 

x     y

5    1350

6    1716

7    1330

 

Note the value of y rises then falls.

how would you find this?  Play with x values and watch the slope of the line. For some "x" values the line is increasing and others it is decreasing. You need to find roughly where it changes slope. in this case at x = 6 approximately.

 

 

 

 

Answer 2

KT, 

 

This parabola may be a bit "larger" than many of the common examples we typically use. You may need to zoom out a bit to see the shape more clearly. It is always good to play around with the viewing window. If you know how to change the window (if not, let me know what device you're using!), try to make "x" go from something like -15 to +10, and "y" go from something like -600 to +100.