Question: how can i replace or define a part from a result

hello , there , i want ask a Question ,

i have a vector result n hier , and there is a long part with ^1/2 (like unter) , which is not defined before , just from compute ,i want to replace this part with A, and have tried to use subs , but it didnt work . 

And i have tried to define it before compute, and then use subs , aber it also didnt work .

so how can i replace or define this part in the result?



Please Wait...