Related rates

• How to Find the Rates of Change of a Rectangle’s Area, Perimeter, and Diagonal
  Find the instantaneous rates for a rectangle with changing sides: area rate, perimeter rate, and the common rate of its two equal diagonals.
• How to Find the Area in a Ladder Related-Rates Problem
  For a sliding ladder, model the wall, floor, and ladder as a right triangle, then differentiate its area and the fixed-length constraint.
• How to Solve Calculus Word Problems
  Learn a reliable method for calculus word problems: identify the goal, define variables, model the situation, differentiate or integrate, and check units.