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Am nevoie de ajutor la exercitiul 5!!!

Am Nevoie De Ajutor La Exercitiul 5 class=

Răspuns :

a=2rad2-b

b(2rad2-b)=2

(2rad2)b - b^2 - 2 = 0 |•(-1)

b^2 - (2rad2)b + 2 = 0

delta=8-4•2=0 =>b1=b2=2rad2/2=rad2

=>a=rad2

1/rad2 + 1/rad2 = 2/rad2 = 2rad2/2 = rad2

a^2 = 2 = b^2

a^2 + b^2 = 4

a+b=2√2

a ori b=2 ==> b=2/a

a+2/a=2√2

a^2/a+2/a=2√2

(a^2+2)/a=2√2 (inmultim cu a)

a^2+2=2√2a (scadem 2√2a)

a^2-2√2a+2=0 ( formam binomul a^2-2ab+b^2=(a-b)^2 )

(a-√2)^2=0

==> a-√2=0 ==> a=√2

√2+b=2√2

b=2√2-√2

b=√2

1/a+1/b=

1/√2+1/√2=

2/√2=

(2√2)/2=√2

a^2+b^2=

√2^2+√2^2=

2+2=4