Solve: x4 - 5x2 + 4 = 0
A
± 1, ± 5
B
± 3, ± 2
C
± 1, ± 2
D
± 4, ± 1
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Question: Solve: x4 - 5x2 + 4 = 0
Solution:
Given,
x4 - 5x2 + 4 = 0
(x2)2 - 5x2 + 4 = 0
Let
x2 = a
∴ a2 - 5a + 4 = 0
⇒ a2 - 4a - a + 4 = 0
⇒ a(a - 4) - 1(a - 4) = 0
⇒ (a - 4)(a - 1) = 0
∴ a - 4 = 0
⇒ a = 4
⇒ x2 = 4
∴ x = ± 2
and,
a - 1 = 0
⇒ a = 1
⇒ x2 = 1
∴ x = ± 1
∴ x = ± 1, ± 2
0
Updated: 13 hours ago
a4 + 4 এর উৎপাদক কী কী?
Created: 3 months ago
A
(a2 + 2a + 2)(a2 - 2a - 2)
B
(a2 + 2a + 2)(a2 - 2a + 2)
C
(a2 - 2a + 2)(a2 + 2a - 2)
D
(a2 - 2a - 2)(a2 - 2a + 2)
a4 + 4 এর উৎপাদক কী কী?
সমাধান:
a4 + 4
= a4 + 4 + 4a2 - 4a2
= (a2)2 + 2.a2. 2 + 22 - 4a2
= (a2 + 2)2 - (2a)2
= (a2 + 2 + 2a)(a2 + 2 - 2a)
=(a2 + 2a + 2)(a2 - 2a + 2)
0
Updated: 3 months ago
logb a1/4 logc b3 loga c4 এর সমাধান কোনটি?
Created: 21 hours ago
A
1
B
1/4
C
3
D
loga 2
প্রশ্ন: logb a1/4 logc b3 loga c4 এর সমাধান কোনটি?
সমাধান:
logb a1/4 logc b3 loga c4
= {(1/4) logb a} × (3 logc b) × (4 loga c)
= {(1/4) × 3 × 4} logb a × logc b × loga c
= 3 logc a × loga c [ যেহেতু loga b × logb a = logb b]
= 3 loga a
= 3 × 1
= 3
0
Updated: 21 hours ago
22x + 1 = 32x - 1 হলে x এর মান কত?
Created: 1 week ago
A
2
B
3/5
C
1
D
3
প্রশ্ন: 22x + 1 = 32x - 1 হলে x এর মান কত?
সমাধান:
22x + 1 = 32x - 1
বা, 22x + 1 = (25)x - 1
বা, 22x + 1 = 25(x - 1)
বা, 22x + 1 = 25x - 5
বা, 2x + 1 = 5x - 5
বা, 1 + 5 = 5x - 2x
বা, 6 = 3x
বা, x = 6/3
∴ x = 2
0
Updated: 1 week ago
