Login

Let f(x) be the quadratic polynomial.If F(2)=10 f(-2)=-2

Then cofficient of x in f(x) is

Take a standard quadratic equation , we have
f(x) = ax2 + bx + c
So at x = -2  , we have f(-2) = -2
Or f(-2) = a(-2)2 + b(-2) + c
4a -2b + c = -2 (1)

And x = 2 , f(2) = 10 
or f(2) =  a(2)2 + (2)b + c = 10 
Or 4a + 2b + c = 10  (2)

So on solving (1) and (2) , we have
-4b = -12
Or b = 3
Hence the coefficient of x is b = 3

  • 1
View Full Answer

Assume f ( x ) is any quadratic polynomial a x 2 + b x + c

Now, substitute x = 2 in f ( x ) and you'll get the answer as 4 a + 2 b + c = 10 .... ( 1 )

Again , substitute x = - 2 in f ( x ) and you'll get the answer as 4 a - 2 b + c = - 2 ..... ( 2 )

Deduct ( 2 ) from ( 1 ) and the result is b = 3 that is the coefficient of x in f ( x )

  • 0
What are you looking for?