Quick Question
What is the value of the slope of the line whose graph is that of the sum of the two linear functions 2x and 3x?
Answer
5. First note that the question makes sense because 2x + 3x = 5x implies that the sum of the two linear functions is again a linear function. Moreover, the graph of the sum has a slope that is the sum of the slopes of the beginning two. In our new language, this says that the derivative of the sum of the two functions is the sum of the two derivatives.
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