If f(2)=0 and f(-1)=0 then which of the following must be a factor of f(x)? a) x+2 b) x-1 c)#x^2+x-2# d) #x^2-x-2# e) none of these
1 Answer
Mar 17, 2018
Explanation:
#"using the "color(blue)"factor theorem"#
#"If "f(a)=0" then "(x-a)" is a factor of "f(x)#
#"here "f(2)=0" and "f(-1)=0#
#rArr(x-2)" and "(x+1)" are factors of "f(x)#
#rArrf(x)=k(x-2)(x+1)larrcolor(blue)"k is a multiplier"#
#"let k = 1"#
#rArrf(x)=x^2-x-2#
#rArr"factor of "f(x)" is "x^2-x-2to(d)#
