How do you factor completely #8x^3+1#?
1 Answer
Dec 30, 2015
Use the sum of cubes identity to find:
#8x^3+1 = (2x+1)(4x^2-2x+1)#
Explanation:
The sum of cubes identity can be written:
#a^3+b^3 = (a+b)(a^2-ab+b^2)#
Use this with
#8x^3+1#
#= (2x)^3+1^3#
#= (2x+1)((2x)^2-(2x)(1)+1^2)#
#= (2x+1)(4x^2-2x+1)#
