What is the vertex?

Question

f(X) 2x^2 - 3       Evaluate f(-4) and f(5) and 

Answer 1

Hi Nelly,

 

 What is the vertex?
f(X)= 2x² - 3

Evaluate f(-4) and f(5) and ???  you didn't give the rest of the question.

 

The vertex is the minimum point of the parabola in this case.

 

x=-b

   ----

      2a

 

x=-0

   ----

    2(2)

 

x=0

 

substitute value in

f(X)= 2x² - 3

 

y=2(0)²-3

y=0-3

y=-3

 

So the vertex is (0,-3)

 

f(X)= 2x² - 3

f(-4) =2(-4)²-3

       = 2(16)-3

       =32-3

       =29

 

 

f(5)=2(5)²-3

     = 2(25)-3

      =50-3

      =47

 

ANSWER: The vertex is (0,-3); f(-4) =29 and f(5) =47