Welcome to Westonci.ca, the Q&A platform where your questions are met with detailed answers from experienced experts. Get quick and reliable solutions to your questions from a community of seasoned experts on our user-friendly platform. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

Find the [tex]\( x \)[/tex]-intercepts of the parabola with vertex [tex]\((-4, 2)\)[/tex] and [tex]\( y \)[/tex]-intercept [tex]\((0, -30)\)[/tex].

Write your answer in this form: [tex]\((x_1, y_1), (x_2, y_2)\)[/tex].

If necessary, round to the nearest hundredth.


Sagot :

To find the [tex]\( x \)[/tex]-intercepts of a parabola with vertex [tex]\((-4, 2)\)[/tex] and [tex]\( y \)[/tex]-intercept [tex]\((0, -30)\)[/tex], let's proceed step by step.

### Step 1: Determine the Equation of the Parabola
We start with the vertex form of a quadratic equation:
[tex]\[ y = a(x - h)^2 + k \][/tex]
where [tex]\( (h, k) \)[/tex] is the vertex. Here, [tex]\( h = -4 \)[/tex] and [tex]\( k = 2 \)[/tex]. Substituting these values, we get:
[tex]\[ y = a(x + 4)^2 + 2 \][/tex]

### Step 2: Use the y-intercept to Find [tex]\( a \)[/tex]
We are given the [tex]\( y \)[/tex]-intercept [tex]\((0, -30)\)[/tex]. This point is on the parabola, so we can substitute [tex]\( x = 0 \)[/tex] and [tex]\( y = -30 \)[/tex] into the equation to solve for [tex]\( a \)[/tex]:
[tex]\[ -30 = a(0 + 4)^2 + 2 \][/tex]
[tex]\[ -30 = a(16) + 2 \][/tex]
[tex]\[ -30 - 2 = 16a \][/tex]
[tex]\[ -32 = 16a \][/tex]
[tex]\[ a = -2 \][/tex]

### Step 3: Write the Complete Equation
Now that we know [tex]\( a = -2 \)[/tex], we can write the full equation of the parabola:
[tex]\[ y = -2(x + 4)^2 + 2 \][/tex]

### Step 4: Find the [tex]\( x \)[/tex]-intercepts
The [tex]\( x \)[/tex]-intercepts occur where [tex]\( y = 0 \)[/tex]. Setting [tex]\( y = 0 \)[/tex] in the equation and solving for [tex]\( x \)[/tex] we get:
[tex]\[ 0 = -2(x + 4)^2 + 2 \][/tex]
[tex]\[ -2(x + 4)^2 + 2 = 0 \][/tex]
[tex]\[ -2(x + 4)^2 = -2 \][/tex]
[tex]\[ (x + 4)^2 = 1 \][/tex]

Taking the square root of both sides:
[tex]\[ x + 4 = 1 \quad \text{or} \quad x + 4 = -1 \][/tex]
[tex]\[ x = 1 - 4 = -3 \quad \text{or} \quad x = -1 - 4 = -5 \][/tex]

### Step 5: Verify the Intercepts
The solutions to the equation are [tex]\( x = -3 \)[/tex] and [tex]\( x = -5 \)[/tex].

Thus, the [tex]\( x \)[/tex]-intercepts of the parabola are:
[tex]\[ (-5, 0) \quad \text{and} \quad (-3, 0) \][/tex]

### Final Answer
[tex]\[ \left(x_1, y_1\right), \left(x_2, y_2\right) = (-5, 0), (-3, 0) \][/tex]
Thank you for trusting us with your questions. We're here to help you find accurate answers quickly and efficiently. We hope you found what you were looking for. Feel free to revisit us for more answers and updated information. We're glad you chose Westonci.ca. Revisit us for updated answers from our knowledgeable team.