Question #02e01
1 Answer
Nov 21, 2017
Explanation:
#"given the roots of a polynomial"#
#"say "x=a,x=b,x=c" then"#
#(x-a),(x-b),(x-c)" are the factors of the polynomial"#
#"the polynomial is then the product of the factors"#
#rArrp(x)=a(x-a)(x-b)(x-c)larrcolor(blue)"a is a multiplier"#
#"here the given roots are "x=1" and "x=4sqrt3#
#"to form a cubic (degree 3 polynomial) requires 3 roots"#
#"note that irrational roots usually occur in pairs"#
#x=4sqrt3" is a root then "x=-4sqrt3" is also a root"#
#"the 3 roots are "x=1,x=4sqrt3,x=-4sqrt3#
#rArr(x-1),(x-4sqrt3),(x+4sqrt3)" are factors"#
#rArry=a(x-1)(x-4sqrt3)(x+4sqrt3)larr"let a =1"#
#rArry=(x-1)(x^2-48)#
#rArry=x^3-48x-x^2+48#
#"a possible cubic is "y=x^3-x^2-48x+48#