In the previous section we saw limits that were infinity and itâs now time to take a look at limits at infinity. By limits at infinity we mean one of the following two limits. In other words, we are going to be looking at what happens to a function if we let x get very large in either the positive or negative sense.
Testing the Device. Bellâs assistant, Thomas Watson, was in a nearby room in Bellâs workshop, waiting to see if Bellâs device would work. Bell spoke these famous words into his device: âMr. Watson, come here. Watson heard the words clearly and distinctly, and thus, the first working model of a telephone was born. Although there were other inventors working on similar designs, including one whose patent application was almost on the same day as Bell submitted his, Bellâs invention was the first actual working telephonic device.
In 1876, Scottish emigrant Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice. This instrument was further developed by many others. The telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones rapidly became indispensable to businesses, government, and households, and are today some of the most widely used small appliances.