Find the derivative of at .
1
Explanation
This question asks for the derivative of the function f(x) = x at x = 1. Following the definition of derivative from the textbook (Definition 1), we apply the first principle method. The derivative f'(a) is defined as the limit of [f(a+h) - f(a)]/h as h approaches 0. For the function f(x) = x, substituting values and simplifying yields f'(1) = 1. This matches the pattern seen in Example 5 of the context, where the derivative of 3x at x = 2 was found to be 3.
Solution Steps
Step 1: Let f(x) = x. We need to find f'(1) using the definition: f'(1) = lim(h→0) [f(1+h) - f(1)]/h
Step 2: Substitute f(1+h) = 1+h and f(1) = 1 into the formula: f'(1) = lim(h→0) [(1+h) - 1]/h
Step 3: Simplify the numerator: f'(1) = lim(h→0) h/h = lim(h→0) 1
Step 4: Since the limit of a constant is the constant itself: f'(1) = 1