Matemàtiques - 1r BAT - Successions. Exercicis límits de `1^\infty`



1-Calculeu els límits següents:


    a) `lim (1+1/(5n))^(n/2)`


      `lim (1+1/(5n))^(5n·1/(5n)·n/2)`


      `lim ((1+1/(5n))^(5n))^(1/(5n)·n/2)`


      `lim ((1+1/(5n))^(5n))^(n/(10n))= e^(1/10)`





    b) `lim(1+1/n^2)^n`


      `lim(1+1/n^2)^(n·n/n)`


      `lim(1+1/n^2)^(n^2/n)`


      `lim((1+1/n^2)^(n^2))^(1/n)= e^0=1`





    c) `lim(1+1/n)^(n^2)`


      `lim(1+1/n)^(n·n)`


      `lim((1+1/n)^n)^n= e^n=e^(+\infty)=+\infty`





    d) `lim(1+3/(n+5))^n`


      `lim(1+1/((n+5)/3))^n`


      `lim(1+1/((n+5)/3))^(n·(n+5)/3·3/(n+5))`


      `lim(1+1/((n+5)/3))^((n+5)/3·n·3/(n+5))`


      `lim(1+1/((n+5)/3))^((n+5)/3·(3n)/(n+5))`


      `lim((1+1/((n+5)/3))^((n+5)/3))^((3n)/(n+5))=e^3`





    e) `lim(1+1/(2n))^(3n+1)`


      `lim(1+1/(2n))^(2n·(3n+1)/(2n))`


      `lim((1+1/(2n))^(2n))^((3n+1)/(2n))=e^(3/2)`





    f) `lim ((n+2)/(n+1))^n`


      `lim (1+(n+2)/(n+1)-1)^n`


      `lim (1+(n+2)/(n+1)-(n+1)/(n+1))^n`


      `lim (1+((n+2)-(n+1))/(n+1))^n`


      `lim (1+1/(n+1))^n`


      `lim (1+1/(n+1))^((n+1)·n/(n+1))`


      `lim ((1+1/(n+1))^(n+1))^(n/(n+1))=e^1=e`





    g) `lim((2n+3)/(2n-1))^((n^2+1)/n)`


      `lim(1+(2n+3)/(2n-1)-1)^((n^2+1)/n)`


      `lim(1+(2n+3)/(2n-1)-(2n-1)/(2n-1))^((n^2+1)/n)`


      `lim(1+((2n+3)-(2n-1))/(2n-1))^((n^2+1)/n)`


      `lim(1+4/(2n-1))^((n^2+1)/n)`


      `lim(1+1/((2n-1)/4))^((n^2+1)/n)`


      `lim(1+1/((2n-1)/4))^((2n-1)/4·(n^2+1)/n·4/(2n-1))`


      `lim((1+1/((2n-1)/4))^((2n-1)/4))^((n^2+1)/n·4/(2n-1))`


      `lim((1+1/((2n-1)/4))^((2n-1)/4))^((4n^2+4)/(2n^2-n))=e^(4/2)=e^2`





    h) `lim(2-(n+3)/(n+1))^(3n)`


      `lim(1+1-(n+3)/(n+1))^(3n)`


      `lim(1+(n+1)/(n+1)-(n+3)/(n+1))^(3n)`


      `lim(1+((n+1)-(n+3))/(n+1))^(3n)`


      `lim(1+(-2)/(n+1))^(3n)`


      `lim(1+1/((n+1)/(-2)))^(3n)`


      `lim(1+1/((n+1)/(-2)))^((n+1)/(-2)·(3n)·(-2)/(n+1)`


      `lim((1+1/((n+1)/(-2)))^((n+1)/(-2)))^((-6n)/(n+1))=e^(-6/1)=e^(-6)=1/(e^6)`





    i) `lim (4-(3n)/(n+5))^(n^2)`


      `lim (1+3-(3n)/(n+5))^(n^2)`


      `lim (1+(3n+15)/(n+5)-(3n)/(n+5))^(n^2)`


      `lim (1+15/(n+5))^(n^2)`


      `lim (1+1/((n+5)/15))^(n^2)`


      `lim (1+1/((n+5)/15))^((n+5)/15·n^2·15/(n+5))`


      `lim ((1+1/((n+5)/15))^((n+5)/15))^((15n^2)/(n+5))=e^+\infty=+\infty`





    j) `lim(1-6/n)^(2n)`


      `lim(1+1/(-n/6))^(2n)`


      `lim(1+1/(-n/6))^((-n/6)·(2n)·(-6/n))`


      `lim((1+1/(-n/6))^(-n/6))^((-12n)/n)=e^(-12)=1/(e^12)`





    k) `lim((n^2+5)/(n^2+1))^(5n)`


      `lim(1+(n^2+5)/(n^2+1)-1)^(5n)`


      `lim(1+(n^2+5)/(n^2+1)-(n^2+1)/(n^2+1))^(5n)`


      `lim(1+4/(n^2+1))^(5n)`


      `lim(1+1/((n^2+1)/4))^(5n)`


      `lim(1+1/((n^2+1)/4))^(((n^2+1)/4)·(5n)·(4/(n^2+1)))`


      `lim((1+1/((n^2+1)/4))^((n^2+1)/4))^((20n)/(n^2+1))=e^0=1`





    l) `lim((n^3-3)/(2n^2-6))^(n^3)`


      `lim((n^3-3)/(2n^2-6))^(n^3)=+\infty^(+\infty)=+\infty`