The general equation for PDMA is aiΦi+biΦi+2+ci Φi+1+diΦi-1+eiΦi-2=fi. Which of the following is incorrect? (Note: ‘N’ is the number of unknowns).

The general equation for PDMA is aiΦi+biΦi+2+ci Φi+1+diΦi-1+eiΦi-

1.	The general equation for PDMA is aiΦi+biΦi+2+ci Φi+1+diΦi-1+eiΦi-2=fi. Which of the following is incorrect? (Note: ‘N’ is the number of unknowns).
A.	e2=0
B.	cN-1=0
C.	e1=0
D.	cN=0
Answer» C.