Q How many values of c in the Equation x 3-5x c result in rational roots which are integers Option

d)infinite
11 years agoHelpfull: Yes(4) No(0)
roots to be rational root d=(b^2-4*a*c)=!a perfect square value so for c=1 ,d=21
c=2,d=25-4*2=17,c=5 d=25-20=5. thus answer 3.however see to be rational we 9 roots(x=b^2-4*a*c) and also to be rational it should be in form -b+-root(b^2-4*a*c)/4a.so d!=a perfect square.and also if no. of rational roots asked den it would be 6 as rational roots occur in conjugate pair.as you 9 roots =-b+-root(b^2-4*a*c)/4a.notice the sign after b it(roots) has one + and a -. i.e -b+-(m taking abt this signs)root(b^2-4*a*c).so no. of rational roots=6.however here it has only asked value of c where rational roots occur so answer 3(1,2,5). hope every body would like it. if disagree bhad mai jao.!!!!!!!!!!!!:)
10 years agoHelpfull: Yes(3) No(14)
Rakesh is right...Rohit what u r saying is for equation like ax2+bx+c but here the equation is cubic.
10 years agoHelpfull: Yes(2) No(1)
see unless u know the value of c u cannot jump to the conclusion of finding a rational root so depending upon the constant we can find the roots so its infinite
11 years agoHelpfull: Yes(1) No(0)
can u please explain??
11 years agoHelpfull: Yes(0) No(1)

Q. How many values of c in the Equation x^3-5x+c result in rational roots which are integers?
Option
a)1
b)3
c)0
d)infinite