If log3 (a2 + a) - log3 (a + 1) = 2 then what is the value of a?
A
3
B
6
C
9
D
27
উত্তরের বিবরণ
Question: If log3 (a2 + a) - log3 (a + 1) = 2 then what is the value of a?
Solution:
log3 (a2 + a) - log3 (a + 1) = 2
⇒ log3 {(a2 + a)/(a + 1)} = 2
⇒ log3 {a(a + 1)/(a + 1)} = 2
⇒ log3 a = 2
⇒ a = 32
⇒ a = 9
0
Updated: 1 month ago
হলে x এর মান কত?
Created: 2 months ago
A
4
B
3
C
2
D
1
সমাধান:
36 × 23x - 8 = 32
⇒ 36.23x - 8 = 9
⇒ 23x - 8 = 1/4 = 2-2
⇒ 3x - 8 = -2
⇒ 3x = 6
∴ x = 2
0
Updated: 2 months ago
log10 0.01 = ?
Created: 2 months ago
A
2
B
- 2
C
- 1/2
D
0.02
প্রশ্ন: log10 0.01 = ?
সমাধান:
log10 0.01
= log10(1/100)
= log10(1/102)
= log10(10- 2)
= - 2 log1010
= (- 2) × 1 [ log1010 =1 ]
= - 2
0
Updated: 2 months ago
log(a2/bc) + log(b2/ca) + log(c2/ab) = ?
Created: 1 month ago
A
2 log (a + b + c)
B
log (abc)
C
1
D
0
সমাধান:
আমরা জানি, log(m/n) = log(m) - log(n) এবং log(mp) = plog(m)
সুতরাং,
log(a2/bc) + log(b2/ca) + log(c2/ab)
= (log a2 - log bc) + (log b2 - log ca) + (log c2 - log ab)
= (2log a - log b - log c) + (2log b - log c - log a) + (2log c - log a - log b)
= 2log a - log b - log c + 2log b - log c - log a + 2log c - log a - log b
= (2log a - log a - log a) + (- log b + 2log b - log b) + (- log c - log c + 2log c)
= 0 + 0 + 0
= 0
0
Updated: 1 month ago
