Approximating f(x) with Midpoint, Trapezoidal & Simpson's Rule

  • Context: Graduate 
  • Thread starter Thread starter 413
  • Start date Start date
Click For Summary
SUMMARY

This discussion focuses on approximating the function f(x) = e^(-x^2) using numerical integration methods: Midpoint, Trapezoidal, and Simpson's Rule with n=2. The computed approximations are 0.88420, 0.87704, and 0.82994, respectively. Error estimates for these methods are EM=0.14875, ET=0.07438, and ES=0.13333. The conversation also addresses determining the necessary value of n to ensure error estimates are less than 0.0001 for each method, utilizing the inequality (2*2^3)/(12n^2) < 0.0001 for calculations.

PREREQUISITES
  • Understanding of numerical integration methods: Midpoint Rule, Trapezoidal Rule, Simpson's Rule
  • Familiarity with error estimation techniques in numerical analysis
  • Basic algebra skills for solving inequalities
  • Knowledge of calculus, specifically derivatives and their applications
NEXT STEPS
  • Learn how to derive error bounds for numerical integration methods
  • Study the implications of increasing n on the accuracy of numerical approximations
  • Explore advanced numerical integration techniques beyond basic methods
  • Investigate the behavior of higher-order derivatives for functions similar to f(x) = e^(-x^2)
USEFUL FOR

Students in calculus courses, particularly those studying numerical methods, mathematicians, and anyone interested in improving their understanding of numerical integration and error analysis.

413
Messages
40
Reaction score
0
a) With f(x)= e^-x^2 , compute approximations using midpoint, trapezoidal and simpson's rule with n=2.
I found that from midpoint rule gives 0.88420, trapezoidal rule gives 0.87704, and simpson's rule gives 0.82994.

Then it asks me to
Compute the error esimates for midpoint, trapezoidal, simpson's. Carefully examine the extreme values of f ''(x). You may use that |f ''''(x)| < 12 for 0<x< 2. (the < signs all mean less than or equal to).
I found that EM=0.14875, ET=0.07438, ES=0.13333

do my answers seem correct?

My question is how big should we take n to guarntee absolute value of ET <0.0001? and for EM<0.0001 and ES<0.0001?
How would you figure this question out?
 
Physics news on Phys.org
for how big should take n to guarntee absolute value

for example with ET <0.0001 plug in all the value for K, a, b

so in your case, K is 2, a is 0, b is 2

so it would be (2*2^3)/(12n^2) < 0.0001 and just do it as algebra question

(2*2^3)/(12*0.0001) < n^2 and find the square root of n

just curious, are you also taking MATH 152 in SFU? coz i did this question too =)
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
10K
  • · Replies 4 ·
Replies
4
Views
2K