ANSWER
Vertex form:

Vertex
V(-4,-11)
EXPLANATION
The given expression is

We complete the square to get the vertex form.
Add and subtract half the square of the coefficient of x.


The vertex is
V(-4,-11)
We will use double angle identities:
cos (5x ) = sin (10x )
cos (5x ) = 2 cos (5x ) sin ( 5x )
cos ( 5 x) - 2 cos ( 5 x ) sin ( 5x ) = 0
cos ( 5 x ) · [ 1 - 2 sin (5 x) ] = 0
cos ( 5 x ) = 0 or : 1 - 2 sin (5 x) = 0
5 x = π/2 +kπ, k∈Z sin (5 x) = 1/2
x1 = π/10 + kπ/5 5 x = π/6+2kπ , k∈ Z
5 x = 5π/6 +2kπ , k∈ Z
x 2 = π/30 +2kπ/5
x 3 = π/9 + 2kπ/5
Answer:
Subtract 4 from each side
Step-by-step explanation:
x + 4 > -8
Subtract 4 from each side
x + 4-4 > -8-4
x>-12
You use the slope formula, (y2-y1/x2-x1)