 #1
chwala
Gold Member
 2,131
 281
 Homework Statement:

Classify the second order linear pde, given by;
##U_t +2U_{tt}+3U_{xx}=0##
 Relevant Equations:
 use of discriminant
Now i learned how to use discriminant i.e ##b^24ac## and in using this we have;
##b^24ac##=##0(4×3×2)##=##24<0,## therefore elliptic.
The textbook has a slight different approach, which i am not familiar with as i was trained to use the discriminant at my undergraduate studies...
see textbook approach here;
and the textbook solution is here;
and i also checked wikipedia on this and they have used the discriminant approach. See the approach here; ( i am comfortable with this approach)
Both approaches should be fine, one can use either approach...correct?
##b^24ac##=##0(4×3×2)##=##24<0,## therefore elliptic.
The textbook has a slight different approach, which i am not familiar with as i was trained to use the discriminant at my undergraduate studies...
see textbook approach here;
and the textbook solution is here;
and i also checked wikipedia on this and they have used the discriminant approach. See the approach here; ( i am comfortable with this approach)
Both approaches should be fine, one can use either approach...correct?