[✓] Calculate the following mathematical expression in W|A?

Posted 10 months ago
754 Views
|
4 Replies
|
2 Total Likes
|
 Hello, I am a new user and this is my first post; I'm from Italy (sorry for bad English); I have difficulty in put this data into the online calculator This is my input data (2a-(√4(a)^2)^1/3)/(√2a-(√2a)^(1/3) I haven't understood yet how to modify the syntaxIs there someone who could help me??? Thanks!!!
4 Replies
Sort By:
Posted 10 months ago
 Hi,try this:http://www.wolframalpha.com/input/?i=(2a-(4a%5E2)%5E1%2F3)%2F(Sqrt(2a)-(2a)%5E(1%2F3))Cheers,Marco
Posted 10 months ago
 This is awesome! Thanks!!!
 Hi,there is not bug in the Wolfram|Alpha. But your expected result is not a general result; i.e you make additional assumptions. If you assume that a is a real number that is positive then the term simplifies to yours. But if a<0 for example Wolfram|Alpha's solution is more appropriate. If you go to one of the (free) cloud products (not Wolfram|alpha) and type in: FullSimplify[(2 a - (4 a^2)^(1/3))/(Sqrt[2 a] - (2 a)^(1/3)), Assumptions -> a \[Element] Reals && a > 0 ] you will get the result you expect. For example: Simplify[2^(1/3) a^(1/3) + Sqrt[2] Sqrt[a] == (2 a - (4 a^2)^(1/3))/(Sqrt[2 a] - (2 a)^(1/3)),Assumptions -> a \[Element] Reals && a > 0 ] evaluates to True, whereas Simplify[2^(1/3) a^(1/3) + Sqrt[2] Sqrt[a] == (2 a - (4 a^2)^(1/3))/(Sqrt[2 a] - (2 a)^(1/3))] evaluates to (a^(2/3) - (a^2)^(1/3))/((-1 + 2^(1/6) a^(1/6)) a^(1/6)) == 0 Cheers,Marco