Question

If p(x)=ax2+bx+c and a+b+c=0 then one zero is
a)-b/a
b)c/a
c)b/c
d)none of these
PLZZZ HELP.....

Answer 1

Answer:

b) c/a

Step-by-step explanation:

ax2+bx = -c

a+b = -c

therefore ax2 + bx = a + b

by observation you can see that x=1 is a solution

since product of roots = c/a, the second root is c/a

Answer 2

Given:

If p(x)=ax2+bx+c and a+b+c=0

To Find:

then one zero is

a)-b/a

b)c/a

c)b/c

d)None of these

Solution:

Before solving this question lets have a basic idea that

Let A and B be the two roots of equation ax^2+bx+c=0 then we can say that,

the sum of the roots is equal to

A+B=-b/a

and the product of the roots is equal to

A*B=c/a

Now in this question, it is given that

a+b+c=0

c=-(a+b)        -(1)

Now taking the given polynomial and put the value of c as stated in equation 1

$ax^{2} +bx=-c\\ax^{2} +bx=a+b$

Then it can be clearly observed that '1' is one of the roots of the polynomial

Now we will use the product of two roots formula to find the other root

A*B=c/a

1*B=c/a

B=c/a

so the other root is c/a

Hence, the correct option is (b).