Convert to scientific notation.
1 answer:
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Answer:
1.8 mph
Step-by-step explanation:
Speed of the steamer in still water is 18 mph.
Speed of the current = x mph.
1. The steamer going downstream traveled the distance between two ports in 3 hours. Traveling downstream the current "helps" the steamer, then the speed is 18 + x mph.
The distance traveled downstream = 3(18 + x) miles.
2. The steamer going upstream traveled the distance between two ports in 3 hours 40 minutes that is hours. Traveling upstream the current "interferes" the steamer, then the speed is 18 - x mph.
The distance traveled upstream miles.
3. The distances are the same, so
Solve this equation:
So the easiest method to find the vertex (the minimum in this case) to do this is to find the axis of symmetry, then plug it into the function.
Firstly, the equation to find the axis of symmetry is , with b = x coefficient and a = x^2 coefficient. The equation equation can be solved as such:
Since the vertex falls on the axis of symmetry, we know that the x-coordinate of the vertex is -2.5. Now to solve for the y-coordinate, plug in x with -2.5 and solve as such:
Now putting it all together, our minimum value (vertex) is (-2.5,-12.25).