Advertisements
Advertisements
प्रश्न
If `x - 1/x = 7` then find the value of `x^2 + 1/x^2`.
If `x - 1/x = 7`, find the value of `x^2 + 1/x^2`.
योग
Advertisements
उत्तर
Given, `x - 1/x = 7`
Since, `(x - 1/x)^2 = x^2 + 1/x^2 - 2 xx x xx 1/x` ...[Using the identity, (a – b)2 = a2 + b2 – 2ab]
∴ `7^2 = x^2 + 1/x^2 - 2`
⇒ `x^2 + 1/x^2 = 49 + 2`
⇒ `x^2 + 1/x^2 = 51`
shaalaa.com
क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
APPEARS IN
संबंधित प्रश्न
Expand (7m − 4)2
Expand `("a"-1/"a")^2`
Factorise the following expressions
y2 – 10y + 25
Evaluate the following, using suitable identity
9982
Factorise the following using suitable identity
x2 – 8x + 16
Using identity, find the value of (4.9)2
Factorised form of 4y2 – 12y + 9 is ______.
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
`x^2/4 - 2x + 4`
Factorise the following.
a2 – 16p – 80
If x – y = 13 and xy = 28, then find x2 + y2.
