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Given a unit circle centered at the origin, find the points where the circle intersects the line $y = 2x + 3$.

Answer 1

Abigail Nelson

Amelia Mitchell

To find the points of intersection between the line $y = 2x + 3$ and the unit circle $x^2 + y^2 = 1$, we substitute $y = 2x + 3$ into the circle’s equation:

$ x^2 + (2x + 3)^2 = 1 $

Expanding and simplifying:

$ x^2 + (4x^2 + 12x + 9) = 1 $

$ 5x^2 + 12x + 9 = 1 $

$ 5x^2 + 12x + 8 = 0 $

Using the quadratic formula where $a = 5, b = 12, c = 8$:

$ x = \frac{-b \pm \sqrt{b^2 – 4ac}}{2a} $

$ x = \frac{-12 \pm \sqrt{144 – 160}}{10} $

$ x = \frac{-12 \pm \sqrt{-16}}{10} $

Since the discriminant is negative, there are no real solutions, meaning the unit circle and the line $y = 2x + 3$ do not intersect.

Answer 2

Alex Thompson

Maria Rodriguez

To determine the intersection points between the circle $x^2 + y^2 = 1$ and the line $y = 2x + 3$, we start by substituting $2x + 3$ for $y$ in the circle’s equation:

$ x^2 + (2x + 3)^2 = 1 $

Expanding and collecting like terms:

$ x^2 + 4x^2 + 12x + 9 = 1 $

$ 5x^2 + 12x + 9 = 1 $

$ 5x^2 + 12x + 8 = 0 $

Applying the quadratic formula $x = frac{-b pm sqrt{b^2 – 4ac}}{2a}$ where $a = 5, b = 12, c = 8$:

$ x = frac{-12 pm sqrt{144 – 160}}{10} $

$ x = frac{-12 pm sqrt{-16}}{10} $

Since the discriminant $(-16)$ is negative, there are no intersections (no real solutions).

Answer 3

Amelia Mitchell

Benjamin Clark

We substitute $y = 2x + 3$ into $x^2 + y^2 = 1$:

$ x^2 + (2x + 3)^2 = 1 $

$ x^2 + 4x^2 + 12x + 9 = 1 $

$ 5x^2 + 12x + 8 = 0 $

Using the quadratic formula:

$ x = frac{-12 pm sqrt{-16}}{10} $

No real solutions since the discriminant is negative.