Keelboats have been used for exploration, such as during the Lewis and Clark Expedition, but were primarily used to transport cargo or settlers in the early 19th century. The process of moving a keelboat upriver was extremely difficult, though current dependent.The earliest keelboat seems to have been a skiff with a plank nailed the length of the bottom to make the boat easier to steer, but by about 1790 the keelboat had become a long narrow craft built on a keel and ribs, with a long cargo box amidships.
A keelboat is a reverine boat that can hold cargo and settlers. The keelboat was used in Lewis and Clark's time. It was used in the early 19th century because it was the most innovative invention at the time, technology was improving by the hour. Used anywhere where theres water for the boat to take cargo and/or settlers from one place to another.
The vertical line test can be used to determine whether a graph represents a function. If we can draw any vertical line that intersects a graph more than once, then the graph does not define afunction because a function has only one output value for each input value.
