Concept of tangent line approximation is important in calculus because it allows simplifying complex calculations and providing insight into the local behavior of functions. 3
This approximation is particularly useful when calculating function values that are difficult to compute directly, especially for nonlinear functions. 2 For example, by looking at the tangent lines at various points, we can get a sense of the overall shape of the function and how it behaves near certain critical points. 1
Some other reasons why tangent line approximation is important: