Math Problem Statement

What are the x-intercepts of the graph of the equation \( y = 2x^2 + x - 3 \)?

Solution

To find the x-intercepts of the graph of the equation y=2x2+x3y = 2x^2 + x - 3, we set y=0y = 0 and solve for xx.

  1. Set up the equation: 2x2+x3=02x^2 + x - 3 = 0

  2. Use the quadratic formula: The quadratic formula states that for any equation of the form ax2+bx+c=0ax^2 + bx + c = 0, the solutions for xx are given by: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} Here, a=2a = 2, b=1b = 1, and c=3c = -3.

  3. Calculate the discriminant: b24ac=1242(3)=1+24=25b^2 - 4ac = 1^2 - 4 \cdot 2 \cdot (-3) = 1 + 24 = 25

  4. Solve for xx: Substitute into the quadratic formula: x=1±2522=1±54x = \frac{-1 \pm \sqrt{25}}{2 \cdot 2} = \frac{-1 \pm 5}{4} This gives two solutions: x=1+54=44=1x = \frac{-1 + 5}{4} = \frac{4}{4} = 1 and x=154=64=32x = \frac{-1 - 5}{4} = \frac{-6}{4} = -\frac{3}{2}

  5. Conclusion: The x-intercepts are x=32x = -\frac{3}{2} and x=1x = 1.

Answer:

The correct choice is: A) 32 and 1\text{A) } -\frac{3}{2} \text{ and } 1

Would you like a further breakdown or have any questions?


Related Questions to Explore:

  1. How does the discriminant determine the nature of the roots of a quadratic equation?
  2. How can the quadratic formula be derived from completing the square?
  3. What are the applications of finding x-intercepts in real-world problems?
  4. How can we graph the function y=2x2+x3y = 2x^2 + x - 3 to visualize the intercepts?
  5. What is the relationship between the coefficients aa, bb, and cc and the shape of the parabola?

Tip:

Remember, the discriminant b24acb^2 - 4ac tells you whether the quadratic equation has real or complex roots. A positive discriminant indicates two real roots, which correspond to x-intercepts on the graph.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
X-Intercepts

Formulas

Quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)

Theorems

Quadratic formula theorem

Suitable Grade Level

Grades 8-10