By "y = −9x2 − 2x" I assume you meant <span>y = −9x^2 − 2x (the "^" symbol represents exponentiation).
Let's find the first derivative of y with respect to x: dy/dx = -18x - 2. This is equivalent to the slope of the tangent line to the (parabolic) curve. Now let this derivative (slope) = 0 and solve for the critical value: -18x - 2 = 0, or
-18x = 2. Solving for x, x = -2/18, or x = -1/9.
When x = -1/9, y = -9(-1/9)^2 - 2(-1/9). This simplifies to y = -9/9 + 2/9, or
y = -7/9.
The only point at which the tangent to the curve is horiz. is (-1/9,-7/9).</span>
Answer: Approximately 72.69 meters
Step-by-step explanation:

To find the answer, set up an equation:

Using this set up we can cross out the units that are on opposite sides of the proportion such as miles and hours, leaving us with the desired units of meters and seconds. Then calculate m/s by multiplying 45 by 1000 meters and then dividing that value by 3600 seconds.
The resulting answer is 45mph = 12.5 m/s
9ft n 3 inches , because 12 inches is a feet ! if you know then you know
Answer:
150
Step-by-step explanation:
300-150