Consider the functionf(x)=4x+8x^1

f(x)=4x+8x^-1

. For this function there are four important intervals:(,A](-,A],[A,B)[A,B),(B,C](B,C],and[C,)[C,) whereA, andCare the critical numbers and the function is not defined atB.

FindA ____________

andB ___________

andC ___________

For each of the following open intervals, tell whetherf(x)

f(x) is increasing or decreasing.

(,A) Select an answerIncreasing or Decreasing

(A,B):Select an answerIncreasing or Decreasing

(B,C):Select an answerIncreasing or Decreasing

(C,)Select an answerIncreasing or Decreasing

Note that this function has no inflection points, but we can still consider its concavity. For each of the following intervals, tell whetherf(x)

f(x)is concave up or concave down.

(,B):Select an answerConcave Up or Concave Down

(B,):Select an answerConcave Upor Concave Down