Question

The graph of the polynomial p(x) = 2x2 + 4x + 3 has its least value at the point ______
(A) (– 1, 9) (B) (1, 9)
(C) (– 1, 1) (D) (0, 3)
Plz solve this..

Answer 1

Answer:

(c)(-1,1)

Step-by-step explanation:

f(x) = 2 x² + 4 x +3

f'(x)= 4x+4

f''(x)=4

To find critical number, f'(x)=0

4x+4=0

x= -1

when x=-1, f''(x) is positive

By second derivative test, f atttains minimum at x= -1.

The minimum value=f(-1)

=2-4+3=1

The minimum point is (-1,1)

Answer 2

Answer:

Correct option is  C

(-1, 1).

Step-by-step explanation:

Given polynomial  

p(x)=2x  2

+4x+3

p(x) attains a minima when  

dx

/dp  =0  

as  

dx

/dp

=4x+4

and  

dx  2

/  d  2  p

=4>0

∵  

dx  2

/  d  2

p

>0

∴it's a point of minima

now,  

dx/dp

=0

given 4x+4=0⇒x=−1

so, p(x) attains minima at x=−1 and p(−1)=2(−1)  

2  +4(−1)+3=1

∴ point is =(−1,1)