local approximation

• tangentLine touching curve once
• linearizationApproximating nonlinear with linear
• TaylorSeamster-derived name
• neighborhoodResidential area nearby
• estimateInformed guess at quantity

gradient · slope · nearby · truncation · interpolation · curve · derivative · infinitesimal · perturbation · fitting · polynomial · smoothness · error · vicinity · convergence · secant · differential · limit