1) 0 ≤ x ≤ 7,5
2) f(x) = 25 × 15 - 4x² = 375 - 4x²
3) f(0) = 375 - 4(0²) = 375
f(0,5) = 375 - 4(0,5²) = 374
f(1) = 375 - 4(1²) = 371
f(2) = 375 - 4(2²) = 359
f(2,5) = 375 - 4(2,5²) = 350
f(3) = 375 - 4(3²) = 339
f(4) = 375 - 4(4²) = 311
f(5) = 375 - 4(5²) = 275
f(6) = 375 - 4(6²) = 231
f(7) = 375 - 4(7²) = 179
f(7,5) = 375 - 4(7,5)² = 150
