0
|
2698 Views
|
2 Replies
|
1 Total Likes
View groups...
Share
GROUPS:

# Getting Integrate to produce the simple analytic result

Posted 11 years ago
 Integrate[Sin[1.5 M+a] Cos[1.5 M+b] Sin[1.5 M+b] , {M, 0, 4 Pi}]  produces -1.22465 x 10^{-16}Cos[a-2.b]+1.22465 x 10^{-16}Cos[a+2.b]+0. Sin[a-2b] + 0.Sin[a+2.b].  But the integral is rigorously zero with rather trivial trigonometric integrations.  One could interpret  the result of Integrate as zero, but why does Mathematica not give the simple answser?  Is there a way to use Integrate on this product  to yield the rigporous analytic result?  Simplify [%] does not eliminate the terms with zero factor.
2 Replies
Sort By:
Posted 11 years ago
 Oh, I forgot:Integrate[ Sin[SetPrecision[1.5, Infinity] M + a] Cos[   SetPrecision[1.5, Infinity] M + b] Sin[   SetPrecision[1.5 , Infinity] M + b], {M, 0, 4 Pi}]would also work...
Posted 11 years ago
 Dear Stanton,please tryIntegrate[Sin[3/2 M + a] Cos[3/2 M + b] Sin[3/2 M + b], {M, 0, 4 Pi}]Mathematica assume that 1.5 etc in your inpute are finite precision numbers. Cheers,M.
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.