Question

Am nevoie urgent. Dau coroana ​

Answer 1

E(x)=(2x+1)/(x-1):(1-3x²/(1-x²) unde

x=R\{±1;±1/2}

a)x=2

E(2)=(5/1):(1-12/(1-4)=5:(1+4)=5:5=1

b)E(x)=(2x+1)/(x-1):(1-3x²/(1-x²)=

(2x+1)/(x-1)×(1-x²)/(1-x²-3x²)=

(2x+1)×(1+x)/(1-4x²)=

(2x+1)×(1+x)/(1-2x)(1+2x)=

(1+x)/(1-2x)

c)E(x)=2

(1+x)/(1-2x)=2

1+x=2-4x

5x=1

x=1/5