Answer:
1) 2 nonreal complex roots
2) 1 Real Solution
3) 16
4) Reflected, narrower by a factor of 2/5, slides right 4 units and slides up 6 (units)
Explanation:
1) The graph does not intercept the x-axis, therefore, there are no real solutions at the point y = 0
We get;
y = a·x² + b·x + c
At y = 6, x = -2
Therefore;
6 = a·(-2)² - 2·b + c = 4·a - 2·b + c
6 = 4·a - 2·b + c...(1)
At y = 8, x = 0
8 = a·(0)² + b·0 + c
∴ c = 8...(2)
Similarly, we have;
At y = 8, x = -4
8 = a·(-4)² - 4·b + c = 16·a - 4·b + 8
16·a - 4·b = 0
∴ b = 16·a/4 = 4·a
b = 4·a...(3)
From equation (1), (2) and (3), we have;
6 = 4·a - 2·b + c
∴ 6 = b - 2·b + 8 = -b + 8
6 - 8 = -b
∴ -b = -2
b = 2
b = 4·a
∴ a = b/4 = 2/4 = 1/2
The equation is therefor;
y = (1/2)·x² + 2·x + 8
Solving we get;
x = (-2 ± √(2² - 4 × (1/2) × 8))/(2 × (1/2))
x =( -2 ± √(-12))/1 = -2 ± √(-12)
Therefore, we have;
2 nonreal complex roots
2) Give that the graph of the function touches the x-axis once, we have;
1 Real Solution
3) The given function is f(x) = 2·x² + 8·x + 6
The general form of the quadratic function is f(x) = a·x² + b·x + c
Comparing, we have;
a = 2, b = 8, c = 6
The discriminant of the function, D = b² - 4·a·c, therefore, for the function, we have;
D = 8² - 4 × 2 × 6 = 16
The discriminant of the function, D = 16
4.) The given function is g(x) = (-2/5)·(x - 4)² + 6
The parent function of a quadratic equation is y = x²
A vertical translation is given by the following equation;
y = f(x) + b
A horizontal to the right by 'a' translation is given by an equation of the form; y = f(x - a)
A vertical reflection is given by an equation of the form; y = -f(x) = -x²
A narrowing is given by an equation of the form; y = b·f(x), where b < 1
Therefore, the transformations of g(x) from the parent function are;
g(x) is a reflection of the parent function, with the graph of g(x) being narrower by 2/5 than the graph of the parent function. The graph of g(x) is shifted right by 4 units and is then slides up by 6 units.