f ( x ) = ( x + 3 )² - 8 = x² + 6 x + 9 - 8 = x² + 6 x + 1
For the quadratic function:
Axis of symmetry is: x = -b/ 2 a, where: a = 1, b = 6 ( because it it in the form:
y = a x² + b x + c ).
Therefore: x = -6 / 2 = -3.
f ( - 3 ) = ( - 3 + 3 )² - 8 = 0 - 8 = - 8
And D = b² - 4 a c = 6² - 4 * 1 * 1 = 36 - 4 = 32 ( greater than 0 ). It means that there are 2 real solutions.
Answer: x = - 3 , vertex : ( - 3 , - 8 ), Number of real solutions : 2.
a 1 = - 3 , a 2 = - 3 , a 3 = - 8 , a 4 = 2.