How do you evaluate the limit of #lim (-x^3+3x^2-4)# as #x->-1#?

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Answer 1 · 2017-06-13T12:26:33

#:. x rarr (-1) lim(-x^3+3x^2-4) =0#

#: x rarr (-0.9999) lim(-x^3+3x^2-4) = -0.0009#

#x rarr (-1^+) lim(-x^3+3x^2-4) = lim(-(-1)^3+3(-1)^2-4) = 0#

#: x rarr (-1.0001) lim(-x^3+3x^2-4) = 0.0009#

#x rarr (-1^-) lim(-x^3+3x^2-4) = lim(-(-1)^3+3(-1)^2-4) = 0#

#:. x rarr (-1) lim(-x^3+3x^2-4) =0# [Ans]

Answer 2 · 2017-06-13T18:10:23

#0#

#"the limit of a polynomial can be evaluated by substitution"#

#rArrlim_(xto-1)(-x^3+3x^2-4)#

#=-(-1)^3+3(-1)^2-4#

#=0#