How do you find all the zeros of #f(x)=2x^3+5x^2-2x-5#?
1 Answer
Aug 5, 2016
Explanation:
This cubic factors by grouping:
#f(x) = 2x^3+5x^2-2x-5#
#=(2x^3+5x^2)-(2x+5)#
#=x^2(2x+5)-1(2x+5)#
#=(x^2-1)(2x+5)#
#=(x^2-1^2)(2x+5)#
#=(x-1)(x+1)(2x+5)#
Hence zeros:
