1. **State the problem:**
We are given two equations:
$$x^2 + y^2 = 4$$
$$y - x = 1$$
We need to find the points of intersection between the circle and the line.
2. **Use the substitution method:**
From the linear equation, express $y$ in terms of $x$:
$$y = x + 1$$
3. **Substitute into the circle equation:**
Replace $y$ with $x + 1$ in the circle equation:
$$x^2 + (x + 1)^2 = 4$$
4. **Expand and simplify:**
$$x^2 + (x^2 + 2x + 1) = 4$$
$$2x^2 + 2x + 1 = 4$$
5. **Bring all terms to one side:**
$$2x^2 + 2x + 1 - 4 = 0$$
$$2x^2 + 2x - 3 = 0$$
6. **Divide the entire equation by 2 to simplify:**
$$\cancel{2}x^2 + \cancel{2}x - \cancel{6/2} = 0$$
$$x^2 + x - \frac{3}{2} = 0$$
7. **Solve the quadratic equation using the quadratic formula:**
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=1$, $b=1$, and $c=-\frac{3}{2}$.
Calculate the discriminant:
$$\Delta = 1^2 - 4 \times 1 \times \left(-\frac{3}{2}\right) = 1 + 6 = 7$$
So,
$$x = \frac{-1 \pm \sqrt{7}}{2}$$
8. **Find corresponding $y$ values:**
Recall $y = x + 1$, so:
$$y = \frac{-1 \pm \sqrt{7}}{2} + 1 = \frac{-1 \pm \sqrt{7} + 2}{2} = \frac{1 \pm \sqrt{7}}{2}$$
9. **Final answer:**
The points of intersection are:
$$\left(\frac{-1 + \sqrt{7}}{2}, \frac{1 + \sqrt{7}}{2}\right) \quad \text{and} \quad \left(\frac{-1 - \sqrt{7}}{2}, \frac{1 - \sqrt{7}}{2}\right)$$
Circle Line Intersection 3C1508
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