Examples with solutions for Parabola of the Form y=(x-p)²+k: Finding a stationary point

Exercise #1

Find the intersection of the function

y=(x+5)2+2 y=(x+5)^2+2

With the Y

Video Solution

Step-by-Step Solution

To find the intersection of the function y=(x+5)2+2 y = (x+5)^2 + 2 with the y-axis, we follow these steps:

  • Step 1: Identify that the intersection with the y-axis occurs when x=0 x = 0 .
  • Step 2: Substitute x=0 x = 0 into the equation y=(x+5)2+2 y = (x+5)^2 + 2 .
  • Step 3: Perform the substitution and simplify: y=(0+5)2+2 y = (0+5)^2 + 2 .
  • Step 4: Simplify further: y=52+2=25+2=27 y = 5^2 + 2 = 25 + 2 = 27 .

Thus, the intersection point with the y-axis is (0,27) (0, 27) .

The correct answer is option 4: (0,27) (0, 27) .

Answer

(0,27) (0,27)

Exercise #2

Find the intersection of the function

y=(x3)24 y=(x-3)^2-4

With the Y

Video Solution

Step-by-Step Solution

The problem asks us to find where the parabola given by y=(x3)24 y = (x-3)^2 - 4 intersects the y-axis. The intersection with the y-axis occurs where x=0 x = 0 . Let's find the value of y y by substituting x=0 x = 0 into the equation:

y=(03)24 y = (0 - 3)^2 - 4

Simplify inside the parentheses:

y=(3)24 y = (-3)^2 - 4

Calculate (3)2(-3)^2:

y=94 y = 9 - 4

Subtract 4 from 9:

y=5 y = 5

Thus, the intersection of the function with the y-axis occurs at the point (0,5) (0, 5) .

The correct answer from the choices provided is (0,5)(0,5).

Answer

(0,5) (0,5)

Exercise #3

Find the intersection of the function

y=(x+2)24 y=(x+2)^2-4

With the X

Video Solution

Step-by-Step Solution

To solve this problem, we need to determine where the parabola y=(x+2)24 y = (x+2)^2 - 4 intersects the x-axis. This occurs where y=0 y = 0 .

Step 1: Set the equation equal to zero to find the x-intercepts:
0=(x+2)24 0 = (x+2)^2 - 4

Step 2: Simplify the equation:
(x+2)2=4 (x+2)^2 = 4

Step 3: Solve for x x by taking the square root of both sides:
x+2=±2 x+2 = \pm 2

Step 4: Solve each equation for x x :
1. x+2=2 x+2 = 2 leads to x=0 x = 0
2. x+2=2 x+2 = -2 leads to x=4 x = -4

Therefore, the points of intersection are (4,0) (-4, 0) and (0,0) (0, 0) , where the parabola intersects the x-axis.

The correct answer to the problem is (4,0),(0,0) (-4, 0), (0, 0) .

Answer

(4,0),(0,0) (-4,0),(0,0)

Exercise #4

Find the intersection of the function

y=(x+3)2+4 y=(x+3)^2+4

With the X

Video Solution

Step-by-Step Solution

To determine where the parabola intersects the x-axis, we solve for x when y=0 y = 0 in the function y=(x+3)2+4 y = (x+3)^2 + 4 .

Set y=0 y = 0 :

0=(x+3)2+40 = (x+3)^2 + 4

Subtract 4 from both sides to isolate the square term:

(x+3)2=4(x+3)^2 = -4

We now assess the equation (x+3)2=4 (x+3)^2 = -4 . A square is always non-negative, meaning that no real number squared gives a negative result. Hence, there's no real value of x satisfying this equation.

Thus, the parabola has no intersection points with the x-axis.

Therefore, the correct answer is that there is no intersection.

Answer

There is no intersection

Exercise #5

Find the intersection of the function

y=(x+2)2+3 y=(x+2)^2+3

With the Y

Video Solution

Step-by-Step Solution

To solve the problem of finding the intersection of the function y=(x+2)2+3 y = (x+2)^2 + 3 with the Y-axis, we will follow these steps:

Let's begin with identifying the point where the function intersects the Y-axis. A point on the Y-axis always has x=0 x = 0 . So, we’ll substitute this value into the function to find the corresponding y-coordinate.

Substitute x=0 x = 0 into the function:

y=(0+2)2+3 y = (0+2)^2 + 3

First, calculate (0+2)2 (0+2)^2 :

(0+2)2=22=4 (0+2)^2 = 2^2 = 4

Then add 3 to the result:

y=4+3=7 y = 4 + 3 = 7

Thus, the intersection point on the Y-axis is (0,7) (0, 7) .

Therefore, the solution to the problem is (0,7) (0, 7) .

Answer

(0,7) (0,7)

Exercise #6

Find the intersection of the function

y=(x+4)21 y=(x+4)^2-1

With the Y

Video Solution

Step-by-Step Solution

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

  • Step 1: Identify the equation of the function y=(x+4)21 y = (x+4)^2 - 1 .

  • Step 2: Since we're finding the intersection with the Y-axis, set x=0 x = 0 .

  • Step 3: Substitute x=0 x = 0 into the equation and solve for y y .

Now, let's work through each step:

Step 1: The equation of the function is already given as y=(x+4)21 y = (x+4)^2 - 1 .

Step 2: To find the Y-intercept, let x=0 x = 0 .

Step 3: Substitute x=0 x = 0 into the equation:

yamp;=(0+4)21amp;=421amp;=161amp;=15 \begin{aligned} y &= (0 + 4)^2 - 1 \\ &= 4^2 - 1 \\ &= 16 - 1 \\ &= 15 \end{aligned}

Therefore, the intersection with the Y-axis is at (0,15) (0, 15) .

Answer

(0,15) (0,15)

Exercise #7

Find the intersection of the function

y=(x+1)25 y=(x+1)^2-5

With the X

Video Solution

Step-by-Step Solution

To solve this problem, follow these steps:

The problem asks to find the intersection of the parabola with the x-axis given by the equation y=(x+1)25 y = (x+1)^2 - 5 . The x-intercepts occur where y=0 y = 0 .

Let's solve the equation for y=0 y = 0 :

(x+1)25=0 (x+1)^2 - 5 = 0

Simplify and solve for x x :

  • Add 5 to both sides: (x+1)2=5 (x+1)^2 = 5
  • Take the square root of both sides: x+1=±5 x+1 = \pm \sqrt{5}
  • Solve for x x by subtracting 1 from both sides: x=1±5 x = -1 \pm \sqrt{5}

This gives two solutions:

  • x=1+5 x = -1 + \sqrt{5}
  • x=15 x = -1 - \sqrt{5}

Therefore, the x-intercepts are (1+5,0)(-1+\sqrt{5}, 0) and (15,0)(-1-\sqrt{5}, 0).

The correct answer is then the pair (1+5,0)(-1+\sqrt{5}, 0) and (15,0)(-1-\sqrt{5}, 0), which matches choice 3:

(51,0),(51,0) (-\sqrt{5}-1,0),(\sqrt{5}-1,0)

Therefore, the solution to the problem is (1+5,0)(-1+\sqrt{5}, 0) and (15,0)(-1-\sqrt{5}, 0)

Answer

(51,0),(51,0) (-\sqrt{5}-1,0),(\sqrt{5}-1,0)

Exercise #8

Find the intersection of the function

y=(x+3)29 y=(x+3)^2-9

With the X

Video Solution

Step-by-Step Solution

To solve the problem of finding the intersection of the function y=(x+3)29 y = (x + 3)^2 - 9 with the x-axis, we need to set y=0 y = 0 because the x-axis is defined by y=0 y = 0 .

Starting with the equation:

(x+3)29=0(x + 3)^2 - 9 = 0

Our goal is to solve for x x . Let's simplify the equation:

Add 9 to both sides:

(x+3)2=9(x + 3)^2 = 9

Next, take the square root of both sides:

x+3=±3x + 3 = \pm 3

This gives us two equations to solve:

  • x+3=3x + 3 = 3
  • x+3=3x + 3 = -3

Solving these equations, we find:

For x+3=3x + 3 = 3:

x=0x = 0

For x+3=3x + 3 = -3:

x=6x = -6

Thus, the x-intercepts are (0,0)(0, 0) and (6,0)(-6, 0). These are the points where the graph intersects the x-axis.

The correct answer, matching the choices given, is choice 3: (0,0),(6,0)(0, 0), (-6, 0).

Answer

(0,0),(6,0) (0,0),(-6,0)

Exercise #9

Find the intersection of the function

y=(x+5)249 y=(x+5)^2-49

With the X

Video Solution

Step-by-Step Solution

To find the intersection of the function y=(x+5)249 y = (x+5)^2 - 49 with the x-axis, we need to solve the equation for y=0 y = 0 .

Set the equation equal to zero:

(x+5)249=0(x+5)^2 - 49 = 0

Add 49 to both sides:

(x+5)2=49(x+5)^2 = 49

Take the square root of both sides, remembering to consider both the positive and negative roots:

x+5=7x + 5 = 7 or x+5=7x + 5 = -7

Solve for xx in both cases:

  • For x+5=7x + 5 = 7:
    x=75x = 7 - 5
    x=2x = 2
  • For x+5=7x + 5 = -7:
    x=75x = -7 - 5
    x=12x = -12

Therefore, the x-intercepts of the function are (12,0)(-12, 0) and (2,0)(2, 0).

Thus, the function intersects the x-axis at these points.

(12,0),(2,0)(-12, 0), (2, 0)

Answer

(12,0),(2,0) (-12,0),(2,0)

Exercise #10

Find the intersection of the function

y=(x7)240 y=(x-7)^2-40

With the Y

Video Solution

Step-by-Step Solution

To find the intersection of the function y=(x7)240 y = (x - 7)^2 - 40 with the y y -axis, we set x=0 x = 0 since this is the defining property of the y y -axis.

Substitute x=0 x = 0 into the function:

  • Compute y=(07)240 y = (0 - 7)^2 - 40 .
  • Calculate y=(7)240 y = (-7)^2 - 40 .
  • This simplifies to y=4940 y = 49 - 40 .
  • Thus, y=9 y = 9 .

The point of intersection on the y y -axis is therefore (0,9)(0, 9).

Therefore, the solution to the problem is (0,9)(0, 9).

Answer

(0,9) (0,9)