Approximate the number 4 sqrt(1.1) using the tangent line approximation to the curve y = f(x) when x is near the target 1.1? **hint use: f(x) ≈ f(a) + f′(a)(x−a)**

1 Answer
Jul 14, 2016

See below

Explanation:

Define f(x) = 4sqrt(x). According to the tangent line given as

y = f(1.1)+f'(1.1)(x-1.1)

and substituting f'(1.1) =2/sqrt(1.1) we have

y = 4sqrt(1.1)+2/sqrt(1.1)(x-1.1)

Attached a comparative plot with y = 4sqrt(x) in blue and
y = 4sqrt(1.1)+2/sqrt(1.1)(x-1.1) in red, near the point x = 1.1

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