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Ch 4.6 Related Rates Graphical, Numerical, Algebraic by Finney Demana, Waits, Kennedy. Differentiation With Respect to Different Variables. The volume of a cone can be expressed as:. a) Find dV/dt if V, r, and h are all functions of time.
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Ch 4.6 Related RatesGraphical, Numerical, Algebraic by Finney Demana, Waits, Kennedy
Differentiation With Respect to Different Variables The volume of a cone can be expressed as: a) Find dV/dt if V, r, and h are all functions of time. b) Find dV/dt if r is constant so that V and h are functions of time. c) Find dV/dt if V is constant so that only r and h are functions of time.
Differentiation With Respect to Different Variables The volume of a cone can be expressed as: a) Find dV/dt if V, r, and h are all functions of time. b) Find dV/dt if r is constant so that V and h are functions of time. c) Find dV/dt if V is constant so that r and h are functions of time.
Related Rate Example A hot-air balloon rising straight up from a level field is tracked by a range finder 500 feet from the lift-off point. At the moment the range finder’s elevation angle is π/4, the angle is increasing at the rate of .14 radians/min. How fast is the balloon rising at that moment?
h R.F. 500 ft Related Rate Example A hot-air balloon rising straight up from a level field is tracked by a range finder 500 feet from the lift-off point. At the moment the range finder’s elevation angle is π/4, the angle is increasing at the rate of .14 radians/min. How fast is the balloon rising at that moment?
Steps to Solving a Related Rate Problem • Identify the variable whose rate of change we want and the variables whose rate of change we have. • Draw a picture and label with values and variables. • Write an equation relating the variable wanted with known variables. • Differentiate implicitly with respect to time. • Substitute known values • Interpret the solution and reread the problem to make sure you’ve answered all the questions.
z y .6 x .8
Related Rate Example Water runs into a conical tank at the rate of 9 ft3/min. The tank stands point down and has a height of 10 ft and a base radius of 5 ft. How fast is the water level rising when the water is 6 ft deep?
5 ft r 10 ft h Related Rate Example Water runs into a conical tank at the rate of 9 ft3/min. The tank stands point down and has a height of 10 ft and a base radius of 5 ft. How fast is the water level rising when the water is 6 ft deep?
Related Rate Example • A 13 ft ladder is leaning against a wall. Suppose that the base of the ladder slides away from the wall at the constant rate of 3 ft/sec. • Show how the motion of the two ends of the ladder can be represented by parametric equations. • What values of t make sense in this problem. • Graph using a graphing calculator in simultaneous mode. State an appropriate viewing window. (Hint: hide the coordinate axis). • Use analytic methods to find the rates at which the top of the ladder is moving down the wall at t = .5, 1, 1.5 and 2 sec. How fast is the top of the ladder moving as it hits the ground?
Related Rate Example • A 13 ft ladder is leaning against a wall. Suppose that the base of the ladder slides away from the wall at the constant rate of 3 ft/sec. • Show how the motion of the two ends of the ladder can be represented by parametric equations. • What values of t make sense in this problem. • { 0 < t < 13/3 }
Related Rate Example • Graph using a graphing calculator in simultaneous mode. State an appropriate viewing window. (Hint: hide the coordinate axis). t: [0,4] x: [0,13] y: [0, 13] • 4. Use analytic methods to find the rates at which the top of the ladder is moving down the wall at t = .5, 1, 1.5 and 2 sec. How fast is the top of the ladder moving as it hits the ground?