It is rounded to the hundredths.
Answer:
x1, x2 = 4.74 , -2.74
Step-by-step explanation:
To find the roots of a quadratic function we have to use the bhaskara formula
ax^2 + bx + c
x^2 - 2x - 13
a = 1 b = -2 c = -13
x1 = (-b + √ b^2 - 4ac)/2a
x2 =(-b - √ b^2 - 4ac)/2a
x1 = (2 + √ (2^2 - 4 * 1 * (-13)))/2 * 1
x1 = (2 + √ (4 + 52)) / 2
x1 = (2 + √ 56 ) / 2
x1 = (2 + 7.48) / 2
x1 = 9.48 / 2
x1 = 4.74
x2 = (2 - √ (2^2 - 4 * 1 * (-13)))/2 * 1
x2 = (2 - √ (4 + 52)) / 2
x2 = (2 - √ 56 ) / 2
x2 = (2 - 7.48) / 2
x2 = -5.48 / 2
x2 = -2.74
Putting a ladder up against a straight wall. The sides of the triangle are:
1: the ladder
2: the walls
3: the ground from the wall to the ladder
You have the correct axis of symmetry value. Nice work.
Plug that x value into the equation to get...
y = -2x^2 - 12x - 10
y = -2*(-3)^2 - 12*(-3) - 10 <<-- replace every x with -3; then use PEMDAS
y = -2*(9) - 12*(-3) - 10
y = -18 + 36 - 10
y = 18 - 10
y = 8
The vertex is the ordered pair (-3, 8)
Note: the axis of symmetry is the vertical line through the vertex