Constant is the scale term in proportionality. Suppose one variable is dependent on the other and one variable become twice, other becomes also twice and if one becomes half, other too becomes half., but they are two different variables which are no-where linked (like cost(money) vs quantity). Quantity and cost are two different things but they abridge a mathematical relation of proportionality. So in the mathematics to abridge these two different variables, we need something. Constant serves that purpose.
Answer:

Step-by-step explanation:
Vertex form of a quadratic equation;

Vertex of the parabolas (h, k)
The vertex of the parabola is either the minimum or maximum of the parabola. The axis of symmetry goes through the x-coordinate of the vertex, hence h = -3. The minimum of the parabola is the y-coordinate of the vertex, so k= 7. Now substitute it into the formula;

Now substitute in the given point; ( -1, 9) and solve for a;

Hence the equation in vertex form is;

In standard form it is;

A, B, and C. all of them are reasonable choices and wouldn’t give any conclusion, because not everyone has the flu
Make a drawing with a right triangle.
The opposite side, y, is the height of the dam less 1.65 m
The base or adjacent side is 90 m
The angle between the two sides is 90 m.
Then tan (26) = y / 90
y = 90 tan(26) = 90 (0.4877) = 43.90 m
The height of the dam is 43.90m + 1.65m = 45.55 m