Answer:
The vertex is: 
Step-by-step explanation:
First solve the equation for the variable y

Add 4y on both sides of the equation


Notice that now the equation has the general form of a parabola

In this case

Add
and subtract
on the right side of the equation


Factor the expression that is inside the parentheses

Divide both sides of the equality between 4


For an equation of the form

the vertex is: (h, k)
In this case

the vertex is: 
In all right triangles, the ratio between a leg and the hypothenuse is the sine of the angle opposite to the leg.
So, in your case, we have

In order to find XY, we have

So, the ratio for the sine is

30x-15
Step-by-step explanation: