Answer:
a) y = (x + 1)^2 - 3
b) minimum
c) (-1, -3)
Step by step:
We start with the equation:
y = x^2 + 2*x - 2
First, we want to complete the square to write the equation in the vertex form.
y = (x - h)^2 + k
Such that the vertex is (h, k)
To complete the square, we can write this as:
y = x^2 + 2*1*x - 2
Now we can add and subtract 1
y = x^2 + 2*1*x + 1 - 1 - 2
y = (x^2 + 2*1*x + 1) - 3
The thing inside the parentheses can be written as:
x^2 + 2*1*x + 1 = (x + 1)^2
Then the quadratic equation will be written as:
y = (x + 1)^2 - 3
This is the vertex form.
b) Now we want to know if the vertex is a minimum or a maximum.
Remember that the leading coefficient tells use if the graph of the function opens up or down.
If the leading coefficient is positive, the graph opens up (then the vertex is a minimum)
If the leading coefficient is negative, the graph opens down (then the vertex is a maximum)
In this case, we can write:
y = 1*(x + 1)^2 - 3
The leading coefficient is 1, positive.
Then the vertex is a minimum.
c) The coordinates of the vertex are:
Remember that in the vertex form:
y = (x - h)^2 + k
the vertex is (h, k)
Then the vertex of our equation is:
(-1, - 3)