Find the value of a for which (x + 2a) is a factor of (x5−4a2x3+2x+2a+3).
ANSWER:
Let f(x)=x5–4a2x3+2x+2a+3
It is given that (x + 2a) is a factor of f(x).
Using factor theorem, we have
f(−2a) = 0
⇒(−2a)5−4a2×(−2a)3+2×−2a+2a+3=0⇒−32a5−4a2×−8a3+2×−2a+2a+3=0⇒−32a5+32a5−4a+2a+3=0⇒−2a+3=0⇒2a=3⇒a=32
Thus, the value of a is 32