Find the linear approximation of LaTeX:  \displaystyle f(x) = \ln{\left(x + 1 \right)} at LaTeX:  \displaystyle a = 0 and use it to approximate LaTeX:  \displaystyle \ln{1.49}

Using the formula for the linearization LaTeX:  \displaystyle L(x) = f'(a)(x-a)+f(a) gives: LaTeX:  f(x) = \log{\left(x + 1 \right)} \approx L(x) = x  To approximate LaTeX:  \displaystyle \ln({1.49}) use LaTeX:  \displaystyle x = 1.49-1 = 0.49 . LaTeX:  \ln({1.49}) = f(0.49)  \approx L(0.49) = 0.49