1. **State the problem:** We have a circle defined by the equation $$x^2 + y^2 = 25$$.
2. **Find the centre and radius:** The general form of a circle equation is $$ (x - h)^2 + (y - k)^2 = r^2 $$ where $ (h, k) $ is the centre and $ r $ is the radius.
3. **Identify centre and radius:** Here, the equation is $$ x^2 + y^2 = 25 $$ which can be rewritten as $$ (x - 0)^2 + (y - 0)^2 = 5^2 $$.
So, the centre is $$ (0, 0) $$ and the radius is $$ 5 $$.
4. **Show that the point (3, -4) lies on the circle:** Substitute $x=3$ and $y=-4$ into the circle equation:
$$ 3^2 + (-4)^2 = 9 + 16 = 25 $$
Since the left side equals the right side, the point lies on the circle.
5. **Find two other points on the circle:** Choose values for $x$ and solve for $y$ or vice versa.
For example, let $x=0$:
$$ 0^2 + y^2 = 25 \Rightarrow y^2 = 25 \Rightarrow y = \pm 5 $$
Points: $$ (0, 5) $$ and $$ (0, -5) $$.
Alternatively, let $y=0$:
$$ x^2 + 0^2 = 25 \Rightarrow x^2 = 25 \Rightarrow x = \pm 5 $$
Points: $$ (5, 0) $$ and $$ (-5, 0) $$.
**Final answers:**
- Centre: $$ (0, 0) $$
- Radius: $$ 5 $$
- Point (3, -4) lies on the circle.
- Two other points on the circle: $$ (0, 5) $$ and $$ (0, -5) $$ (or $$ (5, 0) $$ and $$ (-5, 0) $$).
Circle Points 14E288
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