6.3 Numeric Integration

 

Motivate WHY -  Gives an approximate value for a definite integral when can’t or difficult to find “antiderivative”

 

#4   

 

         

 

Use Riemann sums with Rectangles using Right hand endpoints, left hand endpoints, and midpoints.

 

R4   Right Hand Sum for n = 4

 

 

 

 

L4    Left Hand Sum for n = 4

 

 

 

 

A4    Average of Left and Right Sum

 

 

 

M4   Midpoint Sum for n = 4

 

Online Links to visual Riemann Sums

 

http://www.slu.edu/classes/maymk/Applets/Riemann.html

http://calculusapplets.com/riemann.html

http://math.scu.edu/~dsmolars/ma12/riemann.html

 


Trapezoidal Rule         Recall Area formula for trapezoid  

 

          For one Trapezoid this becomes 

 

 

So if n = 6, Add up 6 trapezoids,

 

 

 

Factor out 

 

 

Generalize to get Trapezoidal Rule:

 

 

 

Use trapezoidal rule for same problem as above with rectangular approximations.

#4   

 

 

 

 

 

 

 

 

 


Error Estimate for Trapezoidal Rule        where M is the maximum value of  on [a,b}

 

Find the Maximum error for #24   using the Trapezoidal Rule

 

 

 

 

 

 

 

 

 

Simpson’s Rule   Approximates area using parabola – n should be an even number

 

 

Use Simpson’s Rule to find:  

 

 

 

 

 

 

 

 

 

 

 

 


Error Estimate for Simpson’s Rule        where M is the maximum value of  on [a,b]

 

Find Error estimate on #24  using Simpson’s Rule

 

 

 

 

 

 

 

 

 

Approximate with Trapezoid, Simpson’s, and find error estimates

 

#18     

 

 

 

 

 

 

 

 

 


Find value of n for required accuracy

Determine how many subintervals are required to guarantee accuracy to within 0.00005 in the approximation of the integral by a) the trapezoidal rule and b) Simpson’s Rule.

#22 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Assignment:  Pg. 507;  3-11 odd, 17-23 odd

 [Calculator 29, 31, 37, 41]