MATHEMATICS1. If x=3 +2V2, then find whether x+is a rational or an irr

1.	MATHEMATICS1. If x=3 +2V2, then find whether x+is a rational or an irrational numo13-1
Answer» x=3+2√2 1/x=1/(3+2√2) rationalising the denominator we get, 1/x=3-2√2/(9-8) [here (a+b)(a-b)=a2-b2; a= 3+2√2; b=3-2√2] x+(1/x)=(3+2√2)+(3-2√2) =6 6 can be written as 6/1 Thus 6 is a rational number it is rational number

MATHEMATICS1. If x=3 +2V2, then find whether x+is a rational or an irrational numo13-1

Answer»

x=3+2√2

1/x=1/(3+2√2)

rationalising the denominator we get,

1/x=3-2√2/(9-8) [here (a+b)(a-b)=a2-b2; a= 3+2√2; b=3-2√2]

x+(1/x)=(3+2√2)+(3-2√2)

6 can be written as 6/1

Thus 6 is a rational number

it is rational number