James10492
Junior Member
- Joined
- May 17, 2020
- Messages
- 50
Hi all, this is driving me nuts, I am probably doing something dumb but would appreciate it if someone could point out what. Thanks in advance.
u2−4u2=(u+2)(u−2)u2=(u+2)A+(u−2)B
u2=A(u−2)+B(u+2)
let u = 2,
then 4 = 4 B, so B = 1
let u = -2,
then 4 = -4 A, so A = -1
so,
(u+2)A+(u−2)B=(u−2)1−(u+2)1
but now,
u−21−u+21=u2−4u2
????
u2−4u2=(u+2)(u−2)u2=(u+2)A+(u−2)B
u2=A(u−2)+B(u+2)
let u = 2,
then 4 = 4 B, so B = 1
let u = -2,
then 4 = -4 A, so A = -1
so,
(u+2)A+(u−2)B=(u−2)1−(u+2)1
but now,
u−21−u+21=u2−4u2
????