Solve for the Symmetrical Axis in the Quadratic f(x) = -2x² + 16

Quadratic Functions with Axis of Symmetry

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=2x2+16 f(x)=-2x^2+16

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Find the axis of symmetry for the function
00:03 The axis of symmetry is the X value at the vertex point
00:06 The point where if you fold the parabola in half, both halves are identical
00:13 Let's examine the function's coefficients
00:21 We'll use the formula to calculate the vertex point
00:26 We'll substitute appropriate values according to the given data and solve for X at the point
00:35 And this is the solution to the problem

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=2x2+16 f(x)=-2x^2+16

2

Step-by-step solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the coefficients a a and b b .
  • Step 2: Apply the symmetry axis formula.
  • Step 3: Simplify the expression to find the solution.

Now, let's work through each step:

Step 1: From the quadratic function f(x)=2x2+16 f(x) = -2x^2 + 16 , we identify the coefficients: a=2 a = -2 and b=0 b = 0 .

Step 2: Using the formula for the axis of symmetry, x=b2a x = -\frac{b}{2a} , we substitute the identified coefficients:

x=02(2) x = -\frac{0}{2(-2)} .

Step 3: Simplifying the expression, we have:

x=0 x = 0 .

Therefore, the solution to the problem is the axis of symmetry: x=0 x = 0 .

3

Final Answer

x=0 x=0

Key Points to Remember

Essential concepts to master this topic
  • Formula: Axis of symmetry is x = -b/(2a) for quadratic functions
  • Technique: From f(x) = -2x² + 16, identify a = -2, b = 0
  • Check: Substitute x = 0: f(0) = -2(0)² + 16 = 16 ✓

Common Mistakes

Avoid these frequent errors
  • Incorrectly identifying coefficient b
    Don't assume b equals the constant term 16 = wrong axis calculation! The term 16 has no x, so b = 0 in the standard form ax² + bx + c. Always identify coefficients in order: a (x² term), b (x term), c (constant).

Practice Quiz

Test your knowledge with interactive questions

Given the expression of the quadratic function

Finding the symmetry point of the function

\( f(x)=-5x^2+10 \)

FAQ

Everything you need to know about this question

Why is the coefficient b equal to 0 in this function?

+

In f(x)=2x2+16 f(x) = -2x^2 + 16 , there's no x term (no middle term). The standard form is ax2+bx+c ax^2 + bx + c , so when there's no x term, b = 0.

What does the axis of symmetry tell me about the parabola?

+

The axis of symmetry x=0 x = 0 means the parabola is perfectly balanced around the y-axis. Points on either side of x = 0 are mirror images of each other!

How can I verify that x = 0 is really the axis of symmetry?

+

Check that points equidistant from x = 0 have the same y-value. For example: f(1)=2(1)2+16=14 f(1) = -2(1)^2 + 16 = 14 and f(1)=2(1)2+16=14 f(-1) = -2(-1)^2 + 16 = 14 . Same height!

What if I got a different answer like x = 8?

+

Double-check your formula! Remember it's x=b2a x = -\frac{b}{2a} , not x=c2a x = -\frac{c}{2a} . The constant term 16 is c, not b. Since b = 0, the axis is at x = 0.

Does every quadratic function have an axis of symmetry?

+

Yes, absolutely! Every parabola has exactly one axis of symmetry. It's a vertical line that passes through the vertex (highest or lowest point) of the parabola.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 The Quadratic Function questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations