(1/2){(a + b)2 + (a - b)2} = কত?
A
a2 + b2
B
a2 - b2
C
{(a + b)2/2 - (a - b)2/2}
D
(a + b)2 + (a - b)2
উত্তরের বিবরণ
প্রশ্ন: 1/2 {(a + b)2 + (a - b)2} = কত?
সমাধান:
আমরা জানি,
2(a2 + b2) = (a + b)2 + (a - b)2
∴ a2 + b2 = 1/2 {(a + b)2 + (a - b)2}
0
Updated: 3 months ago
The equation 2x2 + kx + 8 = 0 has two equal roots, then the value of k is-
Created: 1 day ago
A
± 10
B
± 8
C
± 2√2
D
± √3
Question: The equation 2x2 + kx + 8 = 0 has two equal roots, then the value of k is-
Solution:
Here
a = 2, b = k and c = 8
Since the equation has two equal roots
: b2 - 4ac = 0
⇒ (k)2 - 4 × 2 × 8 = 0
⇒ k2 = 64
⇒ k = ± √(64)
k = ± 8
0
Updated: 1 day ago
x + 1/x = 2 হলে x4 + 1/x4 এর মান কত?
Created: 1 month ago
A
1
B
0
C
2
D
1/2
প্রশ্ন: x + 1/x = 2 হলে x4 + 1/x4 এর মান কত?
সমাধান:
দেওয়া আছে,
x + (1/x) = 2
⇒ {x + (1/x)}2 = 22 [বর্গ করে] [(a + b)2 = a2 + 2ab + b2]
⇒ x2 + 2 × x × (1/x) + (1/x)2 = 4
⇒ x2 + (1/x2) = 4 - 2
⇒ {x2 + (1/x2)}2 = 22 [আবার বর্গ করে]
⇒ (x2)2 + 2 × x2 × (1/x2) + (1/x2)}2 = 4
⇒ x4 + 1/x4 = 4 - 2
∴ x4 + 1/x4 = 2
0
Updated: 1 month ago
A solution contains 25% sugar by weight is made sweeter by doubling the amount of sugar. The percent of sugar, by weight, in the new solution is-
Created: 1 day ago
A
33.33%
B
32%
C
40%
D
23.27%
Question: A solution contains 25% sugar by weight is made sweeter by doubling the amount of sugar. The percent of sugar, by weight, in the new solution is-
Solution:
let, solution is 100 unit
amount of sugar = 100 × 25%
= 100 × (25/100)
= 25 unit
by doubling, amount of sweet = 50 unit
∴ solution now = 100 + 25 = 125 unit
∴ percent of sugar = {(50 × 100)/125}% = 40%
0
Updated: 1 day ago
