If x=3-2√2 find the value of x+1/x
Answers
Answer:
Given x = 3+2√2
x +1/x
= 3+2√2 + 1 / 3+2√2
= 3+2√2 + 3-2√2 / 3+2√2(3-2√2)
= 3+2√2 + 3-2√2 / 3² - (2√2)²
= 3+2√2 + 3-2√2/9-8
= 3+2√2 + 3-2√2
= 6 Which can be written in p/q forrm. (6/1)
Therefore it's a rational number!.
Step-by-step explanation:
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Answer:
Given, x =3-2√2
We have to find the value of x+(1/x)
Taking lcm,
x+(1/x) = (x²+1)/x
Replacing the value of x
= {(3-2√2)²+1}/3-2√2
{(3-2√2)²} can be written as (3-2√2)(3-2√2) for our convenience
= {(3-2√2)(3-2√2)+1}/3-2√2
By rationalizing,
= [{(3-2√2)(3-2√2)+1}/3-2√2] × [3+2√2/3+2√2]
= [(3+2√2)(3-2√2)(3-2√2) + 1(3-2√2)] / (3-2√2)(3+2√2)
We know that (3-2√2)(3-2√2) = 9-8 = 1
Placing it in (3+2√2)(3-2√2)
= 1(3-2√2)+1(3-2√2)/1
= 3-2√2+3-2√2
= 3+3
= 6
therefore, the value of x+(1/x) = 6