An estimate is an approximation or prediction of a value based on limited information or calculations. In calculus, estimating refers to finding an approximate value for a mathematical concept, such as the derivative of a function.
Approximation is a method used to find values that are close to the actual value but may not be exact.
Tangent line: A tangent line is a straight line that touches a curve at only one point and represents the slope of the curve at that point.
Riemann sum: A Riemann sum is an approximation technique in calculus used to estimate the area under a curve by dividing it into smaller rectangles.