1. **Problem 1:** Given the hyperbola equation $$\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1$$ and points $(4\sqrt{2}, 3)$ and $(8, 3\sqrt{3})$ lie on the locus, find $a$ and $b$. Also check if points $(4,0)$, $(0,3)$, and $(4,3)$ lie on the locus.
2. **Step 1:** Substitute $(4\sqrt{2}, 3)$ into the hyperbola equation:
$$\frac{(4\sqrt{2})^2}{a^2} - \frac{3^2}{b^2} = 1$$
Simplify:
$$\frac{32}{a^2} - \frac{9}{b^2} = 1 \quad (1)$$
3. **Step 2:** Substitute $(8, 3\sqrt{3})$ into the hyperbola equation:
$$\frac{8^2}{a^2} - \frac{(3\sqrt{3})^2}{b^2} = 1$$
Simplify:
$$\frac{64}{a^2} - \frac{27}{b^2} = 1 \quad (2)$$
4. **Step 3:** Let $X = \frac{1}{a^2}$ and $Y = \frac{1}{b^2}$. Rewrite equations (1) and (2):
$$32X - 9Y = 1$$
$$64X - 27Y = 1$$
5. **Step 4:** Solve the system:
Multiply the first equation by 3:
$$96X - 27Y = 3$$
Subtract the second equation:
$$(96X - 27Y) - (64X - 27Y) = 3 - 1$$
$$32X = 2 \Rightarrow X = \frac{1}{16}$$
6. **Step 5:** Substitute $X=\frac{1}{16}$ into equation (1):
$$32 \times \frac{1}{16} - 9Y = 1 \Rightarrow 2 - 9Y = 1 \Rightarrow 9Y = 1 \Rightarrow Y = \frac{1}{9}$$
7. **Step 6:** Recall $X = \frac{1}{a^2} = \frac{1}{16} \Rightarrow a^2 = 16$ and $Y = \frac{1}{b^2} = \frac{1}{9} \Rightarrow b^2 = 9$.
8. **Step 7:** Check points $(4,0)$, $(0,3)$, and $(4,3)$:
- For $(4,0)$:
$$\frac{4^2}{16} - \frac{0^2}{9} = \frac{16}{16} - 0 = 1$$
Point lies on the locus.
- For $(0,3)$:
$$\frac{0^2}{16} - \frac{3^2}{9} = 0 - 1 = -1 \neq 1$$
Point does not lie on the locus.
- For $(4,3)$:
$$\frac{4^2}{16} - \frac{3^2}{9} = 1 - 1 = 0 \neq 1$$
Point does not lie on the locus.
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9. **Problem 2:** Find the equation of the locus of point $P$ such that the ratio of distances to fixed points $A(1,-1)$ and $B(-1,1)$ is $PA : PB = 1 : 2$.
10. **Step 1:** Let $P = (x,y)$. The distances are:
$$PA = \sqrt{(x-1)^2 + (y+1)^2}$$
$$PB = \sqrt{(x+1)^2 + (y-1)^2}$$
11. **Step 2:** Given $\frac{PA}{PB} = \frac{1}{2}$, square both sides:
$$\frac{PA^2}{PB^2} = \frac{1}{4}$$
12. **Step 3:** Substitute distances squared:
$$\frac{(x-1)^2 + (y+1)^2}{(x+1)^2 + (y-1)^2} = \frac{1}{4}$$
13. **Step 4:** Cross-multiply:
$$4[(x-1)^2 + (y+1)^2] = (x+1)^2 + (y-1)^2$$
14. **Step 5:** Expand:
$$4(x^2 - 2x + 1 + y^2 + 2y + 1) = x^2 + 2x + 1 + y^2 - 2y + 1$$
$$4x^2 - 8x + 4 + 4y^2 + 8y + 4 = x^2 + 2x + 1 + y^2 - 2y + 1$$
15. **Step 6:** Simplify:
$$4x^2 - 8x + 4y^2 + 8y + 8 = x^2 + 2x + y^2 - 2y + 2$$
16. **Step 7:** Bring all terms to one side:
$$4x^2 - x^2 - 8x - 2x + 4y^2 - y^2 + 8y + 2y + 8 - 2 = 0$$
$$3x^2 - 10x + 3y^2 + 10y + 6 = 0$$
17. **Step 8:** Complete the square for $x$ and $y$:
$$3x^2 - 10x + 3y^2 + 10y = -6$$
Divide by 3:
$$x^2 - \frac{10}{3}x + y^2 + \frac{10}{3}y = -2$$
18. **Step 9:** Complete the square:
For $x$:
$$x^2 - \frac{10}{3}x = \left(x - \frac{5}{3}\right)^2 - \left(\frac{5}{3}\right)^2 = \left(x - \frac{5}{3}\right)^2 - \frac{25}{9}$$
For $y$:
$$y^2 + \frac{10}{3}y = \left(y + \frac{5}{3}\right)^2 - \left(\frac{5}{3}\right)^2 = \left(y + \frac{5}{3}\right)^2 - \frac{25}{9}$$
19. **Step 10:** Substitute back:
$$\left(x - \frac{5}{3}\right)^2 - \frac{25}{9} + \left(y + \frac{5}{3}\right)^2 - \frac{25}{9} = -2$$
$$\left(x - \frac{5}{3}\right)^2 + \left(y + \frac{5}{3}\right)^2 = -2 + \frac{50}{9} = \frac{32}{9}$$
20. **Final equation:**
$$\boxed{\left(x - \frac{5}{3}\right)^2 + \left(y + \frac{5}{3}\right)^2 = \frac{32}{9}}$$
This is a circle with center $\left(\frac{5}{3}, -\frac{5}{3}\right)$ and radius $\frac{4\sqrt{2}}{3}$.
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**Summary:**
- $a^2 = 16$, $b^2 = 9$ for the hyperbola.
- Points $(4,0)$ lies on the hyperbola; $(0,3)$ and $(4,3)$ do not.
- The locus with distance ratio 1:2 is a circle centered at $\left(\frac{5}{3}, -\frac{5}{3}\right)$ with radius $\frac{4\sqrt{2}}{3}$.
Hyperbola Locus
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