3 Funzioni ed equazioni di secondo grado ESERCIZI __ 3 5 ______ 243 x2 3x + 1 = 0 [ 2 4 12 9 244 __x2 ___x + __ = 0 5 3 _3_ __ [2; 2] 5 5 ] 245 3x2 + 2(2x + 1) = 0 9x2 9x + 2 = (3x 1)(3x 2) [ ]; [R] 246 47 x(3x + 4) = 2(17 2x) 62 [ 5; 5] 247 10(x 2) + 19 = (5x 1)(1 + 5x) [0; 5 ] _2_ 248 (x 7)(x + 3) + (x 1)(x + 5) = 102 [ 8; 8] 249 (x 1)(x 2)(x 3) (x2 + 3)(x 5) + 2x 33 = 0 [4; 6] 11 ___ 250 (3x 4)2 (6x 7)2 = 0 [1; 9 ] 251 (7x 11)2 (6x + 5)(6x 5) + (2x + 9)2 = (5x 3)2 + 10 [ 13; 2] 252 (x + 2)2 (x + 1)2 = x2 6x + 18 [3; 5] 253 3(3x 1)(x + 3) = 4(2x + 1)(x 3) + 48x [1; 3] _3_ 254 3(x + 2) 2(x + 1)2 = 6(x 1)2 4(x + 1)(x 1) [2; 4 ] 255 (x 1)(2x + 1) = 4(x 1)2 2 [ 2 ; 3] 2 _1_ 2 x x x +x x 1 256 ______ = ______ __ __ 3 4 4 [2; 2] 3 __ 257 1,2 0,4x2 = 0 3x2 3 3x 18 = 0 258 (0,3x + 0,6)2 = 1,44 (0,2x 0,6)2 0,0144 = 0 2 (3x + 1)(x 3) (2x 1)(x + 3) x 9 259 _____________ + 5 = _____________ + ______ 3 260 261 262 263 264 265 266 6 4 2 (x + 1)(x 1) 2x ___ + (x + 1)2 = ____________ 3 3 2 2 x +1 13 x ______ + x = __ + 3x + ___ 2(x + 3) 2 2 2 x 5 5x x2 3 + x2 5x = _____ x2 + _______ 3 3 2 2 1 _1_ _1_ ___ (2 x) + (x 3) = 36 17x + 18 1 1 2 ________ (__ x)(3x + 1) = 2(x + __) 2 2 2 2 2 2x(x 2) _______ (x 2) 7x + 5 (x 1)2 ________ = _______ _______ 3 3 12 2 2x 3 1 3x + ______ = __ + (x + 2)(x 1) 2 2 __ __ __ [ 3 ]; [ 3 ; 2 3 ] [ 6; 2]; [ 2,4; 3,6] 27 ___ [3; 5 ] [ ] [R] [1; 2] _1_ _1_ [3; 2] [ 4; 2] [ 1; 5] [0; 3] 191