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Grade 12th PassAlgebra

Given that ax2 + bx + c = 0 has no real roots and a + b + c
  1. c = 0
  2. c > 0
  3. c
  4. None of these

Profile image of Anjali Singh
11 Years agoGrade 12th Pass
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20 Answers

Profile image of grenade
ApprovedApproved Tutor Answer11 Years ago
will u please complete the question
the data is not sufficient
Profile image of Anjali Singh
11 Years ago
 
Given that ax+ bx + c = 0 has no real roots and a + b + c
  1. A.c = 0
  2. B.c > 0
  3. C.c
  4. D.None of these
  5. This is the question :-)
Profile image of Anjali Singh
11 Years ago
Given that ax+ bx + c = 0 has no real roots and a + b + c less than 0
Profile image of Anjali Singh
11 Years ago
Need the answer reallyfast. PLEASE.
Profile image of grenade
11 Years ago
what about the third option
Profile image of grenade
11 Years ago
just check out that the dicriminant should be less than 0 of the non real roots
Profile image of grenade
11 Years ago
b2 −4ac
Profile image of Anjali Singh
11 Years ago
c less than 0 is the third option
 
I kind of deducted that b2-4ac 2is always positive...so “ac” should also be positive, implying that a and c should bopth either be positive or negative. I don’t know if I am right or not
Profile image of Anjali Singh
11 Years ago
damn the keyboard. I mean b^2 – 4ac always less than 0 so since b^2 is always positive, ac has to be positive
Profile image of grenade
11 Years ago
of course
Profile image of grenade
11 Years ago
an example is here
 
-8x2 +4x-1
i think that the example is fullfilling all the conditions of your question just check out
Profile image of Anjali Singh
11 Years ago
Can you somehow prove it graphically?
Profile image of grenade
11 Years ago
over here image cannot be posted be a student
sorry
Profile image of Anjali Singh
11 Years ago
can you prove it mathematically? Your exapmle fits perfectly but I would really like to know the concept behind the question.
Profile image of grenade
11 Years ago
ok let me tell u then
do
u know Descartes' rule of signs
search it out on google or ask your teacher than the problen is direct
nothing to be confusing just check it out
Profile image of Nicho priyatham
11 Years ago
answer is option c
if a+b+c is less than 0 that means that f(1) is less than  zero 
so  since the given quartatic has no real roots  the whole graph (parabola) lies below x axis 
so f(x)
so c=f(0) is also less than zero
Profile image of Nicho priyatham
11 Years ago
PLZ APPROVE
 
Profile image of grenade
11 Years ago
in your case don’t apply descarets law because this law is for determining the nature of roots of higher degree equations
Profile image of grenade
11 Years ago
in your case don’t apply descarets law because this law is for determining the nature of roots of higher degree equations
Profile image of Arnav Adhiya
7 Years ago
If there are no real zeros, the entire graph is either above the x-axis or below it. Given that the function value at x =1 is negative, the entire function is indeed below the x-axis. Therefore, the function value at x = 0, i.e., c is also below the x-axis and hence c is negative.