Consider the quadratic function: f(x) = 2x ^ 2 + 10x + 8 What are the zeros of the function using completing the square? A w = - 1; x = - 4 B x = 1; x = 1, a = 4 D x + 0, x - 5; x = 0
To find the zeros of the quadratic function using completing the square, we need to set the function equal to zero.
So, 2x^2 + 10x + 8 = 0
First, divide the equation by 2 to simplify it: x^2 + 5x + 4 = 0
Next, we need to complete the square: x^2 + 5x + 25/4 = - 4 + 25/4
(x + 5/2)^2 = 9/4
Now, taking square root on both sides: x + 5/2 = ± 3/2
Now, solving for x:
x + 5/2 = 3/2 or x + 5/2 = -3/2
x = -1 or x = -4
So, the zeros of the function are x = -1 and x = -4.
Therefore, the correct answer is A. x = -1; x = -4.