Apotemi Yayinlari Analitik Geometri -

Compute: ( (1152u+560)(1+u)^2 = (576u^2+560u) \cdot 2(1+u) ). Divide both sides by ( 2(1+u) ) (since ( u>0 )): ( (1152u+560)(1+u) = 2(576u^2+560u) ). Expand LHS: ( 1152u + 1152u^2 + 560 + 560u = 1152u^2 + 1712u + 560 ). RHS: ( 1152u^2 + 1120u ).

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.

Cancel ( 1152u^2 ) both sides: ( 1712u + 560 = 1120u \implies 592u = -560 ) — impossible for ( u>0 ). Apotemi Yayinlari Analitik Geometri

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| ).

Mistake? Let’s recheck derivative carefully. Compute: ( (1152u+560)(1+u)^2 = (576u^2+560u) \cdot 2(1+u) )

( |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. ]

Rotation of ( Q ) about ( B(-2,0) ) by ( +90^\circ ). Vector from ( B ) to ( Q ): [ \vecBQ = Q - B = \left( \frac32x_0 - 1 + 2, \ \frac32y_0 - 0 \right) = \left( \frac32x_0 + 1, \ \frac32y_0 \right). ] Rotation by ( 90^\circ ) CCW: ( (u, v) \mapsto (-v, u) ). So [ \vecBR = \left( -\frac32y_0, \ \frac32x_0 + 1 \right). ] Thus [ R = B + \vecBR = \left( -2 - \frac32y_0, \ 0 + \frac32x_0 + 1 \right). ] Let ( R = (X, Y) ): [ X = -2 - \frac32y_0, \quad Y = 1 + \frac32x_0. ] RHS: ( 1152u^2 + 1120u )

Discriminant: ( 72^2 - 4\cdot 37 \cdot 35 = 5184 - 5180 = 4 ). So ( u = \frac-72 \pm 274 ). Positive root: ( u = \frac-7074 ) (neg) or ( u = \frac-7474 = -1 ) (neg). No positive ( u )?

That means ( h'(u) ) never zero for ( u>0 ) — so minimum at boundary ( u\to 0^+ ) or ( u\to\infty ). Check: As ( u\to 0^+ ), ( h(u) \sim 140u / 1 \to 0 ). As ( u\to\infty ), ( h(u) \sim 144u^2 / u^2 = 144 ). So ( h(u) ) increases from 0 to 144. So minimal area → 0 as ( m\to 0^+ ). But slope ( m>0 ), line through ( B(-2,0) ) — as ( m\to 0 ), line is horizontal ( y=0 ), intersects circle at two points symmetric about center’s vertical line? Wait, ( m=0 ) gives ( y=0 ), circle: ( (x+2)^2 + 1 = 36 ) ⇒ ( (x+2)^2 = 35 ) ⇒ two intersections. Then area formula: ( A=2m|t_1-t_2| ) with ( m=0 ) → area 0? But triangle degenerates? Yes, all points on x-axis: ( A(2,0) ) and ( R_1,R_2 ) on x-axis → collinear → area 0. But ( m>0 ) strictly? Problem says ( m>0 ), so infimum is 0 but not attained. Likely they expect answer for minimal positive area? Then no min, only infimum.