To identify the maximum or minimum value of the function given by the equation y = 2x2 + 32x + 4, we first need to recognize that this is a quadratic function in standard form, y = ax2 + bx + c, where:
- a = 2
- b = 32
- c = 4
Since the coefficient of x2 (i.e., a) is positive (a = 2), the parabola opens upward. This indicates that the function has a minimum value, rather than a maximum.
Finding the Vertex
The vertex of the parabola (where the minimum value occurs) can be found using the formula:
x = -b / (2a)
Plugging in our values:
x = -32 / (2 * 2) = -32 / 4 = -8
Now, we can substitute this x-value back into the original equation to find the corresponding y-value:
y = 2(-8)2 + 32(-8) + 4
Calculating further:
y = 2(64) – 256 + 4 = 128 – 256 + 4 = -124
Thus, the minimum value of the function is -124, occurring at x = -8.
Domain and Range
Domain:
A quadratic function is defined for all real numbers, hence the domain of the function is:
Domain: (-∞, ∞)
Range:
Since the parabola opens upward and has a minimum value of -124, the range of the function is:
Range: [-124, ∞)
In summary, for the function y = 2x2 + 32x + 4:
- Minimum Value: -124 at x = -8
- Domain: (-∞, ∞)
- Range: [-124, ∞)