murcorm
Apr 29, 2008, 10:55 AM
For the function y = 3x^2 + 12x + 9 find:
A. Whether the curve is concave up or down
B. The y-intercept
C. The x-intercept
D. The Vertex
E. The Maximum or Minimum value.
you_know
Apr 29, 2008, 10:58 AM
You can put this in a calculator. I am not good with math but I am sure you can put it in a calculator. Consider tutoring.
galactus
Apr 29, 2008, 11:32 AM
Look at the term in front of the x^2. If it is positive it is concave up. If it is negative, it is concave down.
To find the y intercept, set x=0 and solve.
To find the x-intercept, set y=0 and solve.
To find the vertex, use x=\frac{-b}{2a}
That is the x coordinate of the vertex. PLug that number back into your function to find the y-coordinate.
The vertex will be your minimum value.