Determine if f(x) = 6 - 5x - 3x^2 is linear, quadratic or neither. Identify the leading coefficient and evaluate f(-2)

Question

Determine if f(x) = 6 - 5x - 3x^2 is linear, quadratic or neither. Identify the leading coefficient and evaluate f(-2)

 

choose the correct answer

 

a. niether linear or quadratic

 

b. linear

 

c. quadratic

Answer 1

Hi Keith;

f(x) = 6 - 5x - 3x^2

f(-2)

This is a quadratic equation.  It would normally be written as...

f(x)=-3x²-5x+6

This is because the x² will have the greatest influence on the side of the parabola.  Therefore, it goes first.

 

The leading coefficient is -3.  Its condition of being negative means that the parabola opens downward.

f(-2)=[(-3)(-2)²]-[(5)(-2)]+6

f(-2)=[(-3)(4)]+10+6

f(-2)=-12+10+6

f(-2)=4