Question

if a=2+√5,b=1/a find a^2+b^2​

Answer 1

Answer:

a = 2+√5

b = 1/2+√5

rationalize it

b = -2+√5

a^2 + b^2

(2+√5)^2 + (-2+√5)^2

(2)^2+(√5)^2 -2(2)(√5) + (2)^2+(√5)^2+2(2)(√5)

4+5-4√5+4+5+4√5

4+5+4+5

18