Explore step-by-step evaluations of trinomial functions like k(x) = -4x³ + 2x² – 6 and h(x) = 3x³ – 5x² + 7. Learn how to handle negative coefficients with parentheses and understand the math behind these examples. Dive into the world of trinomials!!

Evaluate the function g(x) = -2x² + 3x at x = -3.

Let x = -3

(-3) × (-3) = 9

-2 × 9 = -18

3 × (-3) = -9

-18 – 9 = -27

g(-3) = -27

Summary: g(-3) = -2 × (-3)² + 3 × (-3) = -2 × 9 – 9 = -18 – 9 = -27


2019NewYorkRegentsJanuaryAlgebraIQuestions2And3Solutions

 


Evaluate the trinomial function f(x) = 2x³ – 3x² + 4x at x = 2.

Let’s start by defining the variable x:

Let x = 2

Now, calculate the cube of x:

2³ = 2 × 2 × 2 = 8

Multiply 2 by the cube of x:

2 × 8 = 16

Calculate the square of x:

2² = 2 × 2 = 4

Multiply -3 by the square of x:

-3 × 4 = -12

Multiply 4 by x:

4 × 2 = 8

Add the three results together to find the value of f(x):

16 – 12 + 8 = 12

Final result:

f(2) = 12

Summary: f(2) = 2 × 2³ – 3 × 2² + 4 × 2 = 2 × 8 – 3 × 4 + 8 = 16 – 12 + 8 = 12


Evaluate the trinomial function h(x) = 3x³ – 5x² + 7 at x = 1.

Let’s start by defining the variable x:

Let x = 1

Now, calculate the cube of x:

1³ = 1 × 1 × 1 = 1

Multiply 3 by the cube of x:

3 × 1 = 3

Calculate the square of x:

1² = 1 × 1 = 1

Multiply -5 by the square of x:

-5 × 1 = -5

Add the constant term:

7

Add the three results together to find the value of h(x):

3 – 5 + 7 = 5

Final result:

h(1) = 5

Summary: h(1) = 3 × 1³ – 5 × 1² + 7 = 3 × 1 – 5 × 1 + 7 = 3 – 5 + 7 = 5


Evaluate the trinomial function k(x) = -4x³ + 2x² – 6 at x = -2.

Note: When inputting negative numbers in calculations, it’s important to use parentheses to ensure the correct order of operations and avoid errors.

Let’s start by defining the variable x:

Let x = -2

Now, calculate the cube of x (using parentheses):

(-2)³ = (-2) × (-2) × (-2) = -8

Multiply -4 by the cube of x:

-4 × (-8) = 32

Calculate the square of x (using parentheses):

(-2)² = (-2) × (-2) = 4

Multiply 2 by the square of x:

2 × 4 = 8

Add the constant term:

-6

Add the three results together to find the value of k(-2):

32 + 8 – 6 = 34

Final result:

k(-2) = 34

Summary: k(-2) = -4 × (-2)³ + 2 × (-2)² – 6 = -4 × (-8) + 2 × 4 – 6 = 32 + 8 – 6 = 34