1.

`lim_(xrarr3) (x^(4)-81)/(2x^(2)-5x- 3) `

Answer» `underset(xrarr0)"lim"(x^(4)-81)/(2x^(2)-5x-3) ((0)/(0))`
`=underset(Xrarr3)"lim"((x^(2)-9)(x^(2)+9))/((x-3)(2x+1))`
`underset(xrarr3)"lim"((x-3)(x+3)(x^(2)+9))/((x-3)(2x+1))`
`=underset(Xrarr3)"lim"((x+3)(x^(2)+9))/(2x+1)`
`=((3+3)(9+9))/(2(3)+1)=(108)/(7)`


Discussion

No Comment Found