Lim (X^3+8/x+2). ? X=-2

2 Answers
Jan 11, 2018

# 12#.

Explanation:

#"The Reqd. Lim.="lim_(x to -2)(x^3+8)/(x+2)#,

#=lim{(x+2)(x^2-2x+4)}/(x+2)#,

#=lim_( x to-2)(x^2-2x+4)#,

#=(-2)^2-2(-2)+4#,

#=12#.

Jan 11, 2018

#12#

Explanation:

#lim_(x->-2)((x^3+8)/(x+2))#

#(x^3+8)/(x+2)=>(x^3+2^3)/(x+2)#

Factor numerator: ( Sum of two cubes )

#(a^3+b^3)=(a+b)(a^2-ab+b^2)#

#((x+2)(x^2-2x+4))/(x+2)#

Cancel factors:

#(cancel((x+2))(x^2-2x+4))/cancel((x+2))#

#x^2-2x+4#

Plug in #-2#

#(-2)^2-2(-2)+4=12#

#:.#

#lim_(x->-2)((x^3+8)/(x+2))=12#