If x+ 1/x =5, then x² + 1/x² =
A. 25
B. 10
C. 23
D. 27
Answers
Answered by
3
Given : x + 1/x = 5
To find : value of x² + 1/x²
Solution :
We have x + 1/x = 5 ……..(1)
On squaring eq 1 both sides,
(x + 1/x)² = 5²
By Using Identity : (a + b)² = a² + b² + 2ab
x² + 1/x² + 2 x × 1/x =25
x² + 1/x² + 2 = 25
x² + 1/x² = 25 - 2
x² + 1/x² = 23
Hence the value of x² +1/x² is 23.
Among the given options option (C) 23 is correct.
HOPE THIS ANSWER WILL HELP YOU…..
Similar questions :
If x+1/x =3, then find the value of x² + 1/x²
https://brainly.in/question/15897808
If x- 1/x= 7, find the value of x³ - 1/x³
https://brainly.in/question/15897613
Answered by
2
Given:
x + 1/x = 5
To find:
x² + 1/x² = ?
Solution:
Identity to be used:
(a + b)² = a² + 2ab + b²
Here, we take:
a = x
b = 1/x
(x + 1/x)² = x² + 2(x)(1/x) + 1/x²
=> 5² = x² + 2 + 1/x²
=> x² + 1/x² = 25 - 2
=> x² + 1/x² = 23
Thus, option (C) 23 is right.
Similar questions