find the limit

Question

                        lim           -     f(x)=__1___

*find the limit  x____ -10                 x+10

 

 

*find the limit        5x^2 +7x-9

   lim                    __________

   x__infinity           -6x^2+2

 

 

*find the limit    lim                 3x^3+5x

                       x___infinity      ______________

                                                 4x^4+10x^3+2

Answer 1

Again, Wyzant formatting has garbled your submissions. Is the first problem -f(x) = (x+10)^-1 , or f(x) = (x+10)^-1? Can't tell.

For the other two, assuming that's x-->+infinity, you simply drop all but the highest power of x from the expressions. So the second case would equate to 5x^2/-6x^2 = (-5/6)*lim(x^2/x^2), or just -5/6; the third problem, assuming x-->+infinity, is governed by the (4x^4)^-1 so will approach 0.

Hope these help you. By the way, the first one is blowing up to infinity, though whether it's positive or negative infinity depends on which side of -10 x is approaching from -- do you see why?