1. **State the problem:**
We have a straight line with gradient (slope) 1 that cuts the y-axis at (0, 7). This line is tangent to the circle defined by the equation $$x^2 + (y - 3)^2 = 8$$ at point K. We need to find the coordinates of point K.
2. **Write the equation of the line:**
Since the slope is 1 and it crosses the y-axis at 7, the line equation is:
$$y = x + 7$$
3. **Substitute the line equation into the circle equation:**
Replace $$y$$ in the circle equation with $$x + 7$$:
$$x^2 + ((x + 7) - 3)^2 = 8$$
Simplify inside the parentheses:
$$x^2 + (x + 4)^2 = 8$$
4. **Expand and simplify:**
$$x^2 + (x^2 + 8x + 16) = 8$$
Combine like terms:
$$2x^2 + 8x + 16 = 8$$
Subtract 8 from both sides:
$$2x^2 + 8x + 8 = 0$$
5. **Divide the entire equation by 2 to simplify:**
$$\cancel{2}x^2 + \cancel{2} \times 4x + \cancel{2} \times 4 = 0$$
becomes
$$x^2 + 4x + 4 = 0$$
6. **Recognize the quadratic:**
$$x^2 + 4x + 4 = (x + 2)^2 = 0$$
7. **Solve for x:**
$$x + 2 = 0 \Rightarrow x = -2$$
8. **Find y using the line equation:**
$$y = x + 7 = -2 + 7 = 5$$
9. **Conclusion:**
The coordinates of the tangent point K are:
$$\boxed{(-2, 5)}$$
Tangent Point 76Bf02
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.