Actually my earlier derivative error: Let’s test numeric: m=1: t^2 coeff 2, -2t -35=0 → t = [2 ± √(4+280)]/4 = [2 ± √284]/4 ≈ (2±16.85)/4 → t1≈4.71, t2≈-3.71. Area=2 1 |4.71+3.71|=2 8.42=16.84. m=0.1: t coeff? (1+0.01)=1.01, -0.2t -35=0, Δ=0.04+141.4=141.44, √≈11.89, |t1-t2|=11.89/1.01≈11.77, Area=2 0.1*11.77≈2.35 — smaller. Yes, decreasing to 0. So indeed infimum 0.
Thus final: minimal area 0 as m→0, but triangle degenerates. For non-degenerate, no minimum, but if they ask for minimizing area among non-degenerate, it's arbitrarily small.
RHS: ( (144u^2+140u)(u+1) = 144u^3 + 144u^2 + 140u^2 + 140u = 144u^3 + 284u^2 + 140u ).
Set numerator=0: ( (288u+140)(u^2+2u+1) = (144u^2+140u) \cdot 2(u+1) ). Divide both sides by 2: ( (144u+70)(u^2+2u+1) = (144u^2+140u)(u+1) ). Apotemi Yayinlari Analitik Geometri
( |t_1 - t_2| = \frac\sqrt\Delta1+m^2 ), where ( \Delta = (-2m)^2 - 4(1+m^2)(-35) = 4m^2 + 140(1+m^2) = 4m^2 + 140 + 140m^2 = 144m^2 + 140 ). So ( |t_1 - t_2| = \frac\sqrt144m^2 + 1401+m^2 ). Thus [ \textArea(m) = 2m \cdot \frac\sqrt144m^2 + 1401+m^2. ]
Point ( Q ) via homothety at ( A(2,0) ): [ Q = A + \frac32(P - A) = \left(2 + \frac32(x_0 - 2), \ 0 + \frac32(y_0 - 0)\right). ] So [ Q = \left( 2 + \frac32x_0 - 3, \ \frac32y_0 \right) = \left( \frac32x_0 - 1, \ \frac32y_0 \right). ]
Equate: ( 144u^3 + 358u^2 + 284u + 70 = 144u^3 + 284u^2 + 140u ). Cancel ( 144u^3 ): ( 358u^2 + 284u + 70 = 284u^2 + 140u ) ( (358-284)u^2 + (284-140)u + 70 = 0 ) ( 74u^2 + 144u + 70 = 0 ) Divide 2: ( 37u^2 + 72u + 35 = 0 ). Actually my earlier derivative error: Let’s test numeric:
Given complexity, likely correct final answer for part (c) in Apotemi style: [ \boxedm \to 0^+,\ \textmin area 0\ (\textnot attained) ] But if they restrict to non-degenerate triangle, maybe minimum at some positive m from a corrected derivative — recheck earlier:
Expand LHS: ( 144u^3 + 288u^2 + 144u + 70u^2 + 140u + 70 = 144u^3 + (288+70)u^2 + (144+140)u + 70 ) ( = 144u^3 + 358u^2 + 284u + 70 ).
Area of triangle ( A(2,0), R_1, R_2 ): Use determinant formula: [ \textArea = \frac12 | x_A(y_1 - y_2) + x_1(y_2 - y_A) + x_2(y_A - y_1) |. ] Better: shift coordinates to simplify. Let ( u = x-2, v = y ) (translate so ( A ) at origin). Then ( A'=(0,0) ), ( R_i' = (t_i - 4, m t_i) ). Area = ( \frac12 | (t_1-4)(m t_2) - (t_2-4)(m t_1) | ) (since ( \frac12 |x_1 y_2 - x_2 y_1| ) in translated coords). Simplify: [ (t_1-4)m t_2 - (t_2-4)m t_1 = m[ t_1 t_2 - 4 t_2 - t_1 t_2 + 4 t_1 ] = m[ 4(t_1 - t_2) ]. ] So Area = ( \frac12 | 4m (t_1 - t_2) | = 2m |t_1 - t_2| ). Thus final: minimal area 0 as m→0, but
[ \text(a) (x+2)^2+(y-1)^2=36 \quad \text(b) Circle, center (-2,1),\ r=6 \quad \text(c) \inf \text area =0 \text as m\to 0^+ ]
Express ( x_0, y_0 ) in terms of ( X, Y ): From ( X ): ( \frac32y_0 = -X - 2 ) ⇒ ( y_0 = -\frac23(X + 2) ). From ( Y ): ( \frac32x_0 = Y - 1 ) ⇒ ( x_0 = \frac23(Y - 1) ).
Given typical contest style, maybe I made algebra slip. But this derivation shows area→0 as m→0. So possibly intended: line through B and tangent to circle? No, that yields one intersection. Hmm.