Keerthana
Posted on

यदि x=3+22x=3+2 sqrt{2}, तो x2+1x2x^{2}+frac{1}{x^{2}} का मूल्य है

a

32

b

34

c

30

d

36

Answer : Option B
Explanation :

x=3+22x=3+2 sqrt{2}

1x=13+22=13+22×322322 herefore frac{1}{x}=frac{1}{3+2 sqrt{2}}=frac{1}{3+2 sqrt{2}} imes frac{3-2 sqrt{2}}{3-2 sqrt{2}}

=32298=322=frac{3-2 sqrt{2}}{9-8}=3-2 sqrt{2}

x+1x=3+22+322=6x+frac{1}{x}=3+2 sqrt{2}+3-2 sqrt{2}=6

x2+1x2=(x+1x)22 herefore x^{2}+frac{1}{x^{2}}=left(x+frac{1}{x} ight)^{2}-2

= (6)2 – 2 = 36 – 2 = 34

Rate This:
NaN / 5 - 1 votes
Profile photo for Dasaradhan Gajendra