Symmetry: Axis of symmetry

Examples with solutions for Symmetry: Axis of symmetry

Exercise #1

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=7x2 f(x)=7x^2

Video Solution

Step-by-Step Solution

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

  • Step 1: Identify the coefficients in the quadratic equation.
  • Step 2: Apply the formula for the axis of symmetry.
  • Step 3: Substitute the coefficients into the formula and solve.

Now, let's work through each step:
Step 1: The quadratic function given is f(x)=7x2 f(x) = 7x^2 which can be written in the form ax2+bx+c ax^2 + bx + c . Here, a=7 a = 7 , b=0 b = 0 , and c=0 c = 0 .
Step 2: We'll use the formula for the axis of symmetry: x=b2a x = -\frac{b}{2a} .
Step 3: Substitute a=7 a = 7 and b=0 b = 0 in the formula:
x=02×7=0 x = -\frac{0}{2 \times 7} = 0 Therefore, the axis of symmetry for the quadratic function f(x)=7x2 f(x) = 7x^2 is x=0 x = 0 .

Therefore, the solution to the problem is x=0 x = 0 , corresponding to choice #3.

Answer

x=0 x=0

Exercise #2

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=4x2+6 f(x)=4x^2+6

Video Solution

Step-by-Step Solution

To find the axis of symmetry for the quadratic function f(x)=4x2+6 f(x) = 4x^2 + 6 , we employ the formula for the axis of symmetry of a parabola given by ax2+bx+c ax^2 + bx + c , which is x=b2a x = -\frac{b}{2a} .

Given f(x)=4x2+0x+6 f(x) = 4x^2 + 0x + 6 , we identify the coefficients from the function:

  • a=4 a = 4
  • b=0 b = 0

Substituting these values into the formula:

x=b2a=02×4=0 x = -\frac{b}{2a} = -\frac{0}{2 \times 4} = 0

Thus, the axis of symmetry for the quadratic function is x=0 x = 0 .

Therefore, the solution to the problem is x=0\mathbf{x = 0}.

Answer

x=0 x=0

Exercise #3

A quadratic equation is graphed below.

What is the axis of symmetry for the graph f(x)=3x2+2 f(x)=3x^2+2 ?

222

Video Solution

Step-by-Step Solution

To determine the axis of symmetry for the function f(x)=3x2+2 f(x) = 3x^2 + 2 , we follow these steps:

  • Identify the coefficients from the function. Here, a=3 a = 3 and b=0 b = 0 . The constant term c=2 c = 2 does not affect the axis of symmetry.
  • Use the axis of symmetry formula for a quadratic function: x=b2a x = -\frac{b}{2a} .
  • Substitute the values for b b and a a into the formula: x=02×3=0 x = -\frac{0}{2 \times 3} = 0 .

This calculation shows that the axis of symmetry for the graph of the quadratic function is x=0 x = 0 .

Thus, the solution to the problem is that the axis of symmetry is x=0 x = 0 .

Answer

x=0 x=0

Exercise #4

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=2x2+8x+4 f(x)=2x^2+8x+4

Video Solution

Step-by-Step Solution

To solve this problem, we'll apply the formula for the axis of symmetry of a quadratic function:

  • Step 1: Recognize the function is f(x)=2x2+8x+4 f(x) = 2x^2 + 8x + 4 .
  • Step 2: Identify the coefficients: a=2 a = 2 and b=8 b = 8 .
  • Step 3: Use the axis of symmetry formula x=b2a x = -\frac{b}{2a} .

Now, substituting the values of a a and b b into the formula:
x=82×2 x = -\frac{8}{2 \times 2} ,
x=84 x = -\frac{8}{4} ,
x=2 x = -2 .

Therefore, the axis of symmetry for the given quadratic function is x=2 x = -2 .

Answer

x=2 x=-2

Exercise #5

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

Video Solution

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 .

Answer

x=0 x=0

Exercise #6

Calculate the axis of symmetry of the quadratic function below:

f(x)=3x2+6x6 f(x)=3x^2+6x-6

Video Solution

Step-by-Step Solution

To find the axis of symmetry for the quadratic function f(x)=3x2+6x6 f(x) = 3x^2 + 6x - 6 , we begin by identifying the coefficients in the general form of a quadratic equation: ax2+bx+c ax^2 + bx + c . Here, a=3 a = 3 , b=6 b = 6 , and c=6 c = -6 .

The formula for the axis of symmetry of a quadratic function is:

x=b2a x = -\frac{b}{2a} .

Substituting the given values into the formula, we have:

x=623 x = -\frac{6}{2 \cdot 3} .

Calculating the above expression, we get:

x=66=1 x = -\frac{6}{6} = -1 .

Thus, the axis of symmetry for this quadratic function is x=1 x = -1 .

Therefore, the solution to the problem is x=1 x = -1 .

Answer

x=1 x=-1

Exercise #7

A quadratic function is graphed below.

What is the axis of symmetry for the graph f(x)=x2+4x f(x)=x^2+4x ?

Video Solution

Step-by-Step Solution

To solve this problem, we'll determine the axis of symmetry using the appropriate formula:

  • Step 1: Identify the coefficients a a , b b , and c c
  • Step 2: Use the axis of symmetry formula
  • Step 3: Substitute the values and solve

Now, let's work through each step:

Step 1: The quadratic function is f(x)=x2+4x f(x) = x^2 + 4x . Here, a=1 a = 1 , b=4 b = 4 , and c=0 c = 0 .

Step 2: Use the axis of symmetry formula x=b2a x = -\frac{b}{2a} .

Step 3: Substitute the values: x=42×1=42=2 x = -\frac{4}{2 \times 1} = -\frac{4}{2} = -2

Therefore, the axis of symmetry for the graph is x=2 x = -2 .

Answer

x=2 x=-2

Exercise #8

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=x2+4x+1 f(x)=x^2+4x+1

Video Solution

Step-by-Step Solution

To solve this problem, we'll apply the formula for finding the axis of symmetry for a quadratic function:

  • Step 1: Identify the coefficients.
    For the quadratic function f(x)=x2+4x+1 f(x) = x^2 + 4x + 1 , we have a=1 a = 1 and b=4 b = 4 .
  • Step 2: Use the formula for the axis of symmetry.
    The axis of symmetry for a quadratic function ax2+bx+c ax^2 + bx + c is given by x=b2a x = -\frac{b}{2a} .
  • Step 3: Substitute the values of a a and b b into the formula.
    Substitute b=4 b = 4 and a=1 a = 1 to get: x=42×1 x = -\frac{4}{2 \times 1} .
  • Step 4: Simplify to find the value of x x .
    This simplifies to x=42=2 x = -\frac{4}{2} = -2 .

Therefore, the axis of symmetry for the given quadratic function is x=2 x = -2 .

Answer

x=2 x=-2

Exercise #9

Given the expression of the quadratic function

The symmetrical axis of the expression must be found.

f(x)=5x225x f(x)=-5x^2-25x

Video Solution

Step-by-Step Solution

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

  • Step 1: Identify the given coefficients a a and b b .
  • Step 2: Apply the formula for the axis of symmetry.
  • Step 3: Perform the necessary calculations to find the axis of symmetry.

Now, let's work through each step:
Step 1: The given quadratic function is f(x)=5x225x f(x) = -5x^2 - 25x , so a=5 a = -5 and b=25 b = -25 .
Step 2: We'll use the axis of symmetry formula x=b2a x = -\frac{b}{2a} .
Step 3: Plugging in our values, we get x=252×5=2510=2.5 x = -\frac{-25}{2 \times -5} = -\frac{25}{-10} = -2.5 .

Therefore, the axis of symmetry for the quadratic f(x)=5x225x f(x) = -5x^2 - 25x is x=212 x = -2\frac{1}{2} .

Answer

x=212 x=-2\frac{1}{2}

Exercise #10

What is the axis of symmetry of the equation?

y=(x5)2+15 y=(x-5)^2+15

Video Solution

Step-by-Step Solution

The first step in solving the equation you presented:

y=(x-5)²+15

is to expand the parentheses:

y=x²-10x+25+15

y=x²-10x+40

From here, we can use the formula to find the X-coordinate of the vertex:

-b/2a

Let's substitute the values from the equation:

-(-10)/2*1 =

10/2=5

The axis of symmetry of the parabola is X=5

Answer

x=5 x=5