Home
Class 14
MATHS
If x=3+2sqrt2, then the value of x^(2)+(...

If `x=3+2sqrt2`, then the value of `x^(2)+(1)/(x^(2))` is:

A

34

B

30

C

36

D

32

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the value of \( x^2 + \frac{1}{x^2} \) given that \( x = 3 + 2\sqrt{2} \). ### Step-by-Step Solution: 1. **Find \( \frac{1}{x} \)**: \[ x = 3 + 2\sqrt{2} \] To find \( \frac{1}{x} \), we rationalize it: \[ \frac{1}{x} = \frac{1}{3 + 2\sqrt{2}} \cdot \frac{3 - 2\sqrt{2}}{3 - 2\sqrt{2}} = \frac{3 - 2\sqrt{2}}{(3 + 2\sqrt{2})(3 - 2\sqrt{2})} \] The denominator simplifies as follows: \[ (3 + 2\sqrt{2})(3 - 2\sqrt{2}) = 9 - 8 = 1 \] Thus, \[ \frac{1}{x} = 3 - 2\sqrt{2} \] 2. **Calculate \( x + \frac{1}{x} \)**: \[ x + \frac{1}{x} = (3 + 2\sqrt{2}) + (3 - 2\sqrt{2}) = 3 + 3 = 6 \] 3. **Square \( x + \frac{1}{x} \)**: \[ (x + \frac{1}{x})^2 = 6^2 = 36 \] 4. **Use the identity to find \( x^2 + \frac{1}{x^2} \)**: The identity states that: \[ (x + \frac{1}{x})^2 = x^2 + \frac{1}{x^2} + 2 \] Therefore, \[ 36 = x^2 + \frac{1}{x^2} + 2 \] 5. **Solve for \( x^2 + \frac{1}{x^2} \)**: \[ x^2 + \frac{1}{x^2} = 36 - 2 = 34 \] ### Final Answer: The value of \( x^2 + \frac{1}{x^2} \) is \( 34 \).
Promotional Banner

Similar Questions

Explore conceptually related problems

If x=3+2sqrt(2), find the value of (x^(2)+(1)/(x^(2)))

If x=2-sqrt(3) , then the values of x^(2)+(1)/(x^(2)) and x^(2)-(1)/(x^(2)) respectively are

"(v) If x=3-2sqrt(2) then find the value of (x^(2)-(1)/(x^(2)))

If x=(1)/(3-2sqrt(2)) ,then the value of ((1)/(x))^(2) is

If x = sqrt3+ sqrt2, then the value of (x +frac(1)(x)) is

If x=3+2 sqrt2 , then the value of x^2+1/x^2 is : यदि x=3+2 sqrt2 , और x^2+1/x^2 का मान ज्ञात करें :