find the value of a if (2x+1) is a factor of (2ײ+ax²-3)..
Attachments:
Answers
Answered by
0
Answer:
Given
f(x)=6x
3
+5x
2
+ax−2
Let us assume
2x+1=0⇒2x=−1⇒x=−
2
1
Since, (2x+1) is a factor of f(x) [Given]
∴ By factor theorem,
f(−
2
1
)=0
⇒6(−
2
1
)
3
+5(−
2
1
)
2
+a(−
2
1
)−2=0
⇒6(−
8
1
)+5(
4
1
)−(−
2
1
)−2=0
⇒−
4
3
+
4
5
−
2
a
−2=0
⇒−3+4−2a−8=0
⇒−6−2a=0
⇒2a=−6
⇒a=−3
Therefore, the value of a is –3.
Answered by
0
Answer:
Since, x+1 is a factor of p(x)=2x
3
+ax
2
+2bx+1
Then, by factor theorem, p(−1)=0
⇒−2+a−2b+1=0⇒a−2b=1 ...(i)
Also,2a−3b=4 ...(ii)
On multiplying (i) by 2 and (ii) by 1, we get
2a−4b=2
−
2
a
+
−
3b=
−
4
−b=−2
∴b=2
On putting b=2 in (i), we get
a−2×2=1⇒a=5
∴a=5,b=2
Step-by-step explanation:
please make as brilliant
Similar questions