1 00:00:00,650 --> 00:00:02,700 要解二次方程 -3x 的平方加上 2 00:00:02,700 --> 00:00:07,620 10x 减去 3 等于 0。 3 00:00:07,620 --> 00:00:09,560 这个方程已经是标准式了。 4 00:00:09,560 --> 00:00:11,060 有很多解法。 5 00:00:11,060 --> 00:00:13,597 如果采用二次方程求解的公式一定可以解出来。 6 00:00:13,597 --> 00:00:14,680 我把方程抄下来。 7 00:00:14,680 --> 00:00:19,435 方程为-3x 的平方加上 10x 减去 3 等于 0。 8 00:00:19,435 --> 00:00:20,810 我打算用二次方程的公式 9 00:00:20,810 --> 00:00:22,720 来解两次,以说明只要我们 10 00:00:22,720 --> 00:00:25,350 正确地使用公式, 11 00:00:25,350 --> 00:00:26,850 就一定能得到该 12 00:00:26,850 --> 00:00:29,900 方程的正确且 13 00:00:29,900 --> 00:00:31,370 一致的解答。 14 00:00:31,370 --> 00:00:34,322 15 00:00:34,322 --> 00:00:36,780 16 00:00:36,780 --> 00:00:37,450 17 00:00:37,450 --> 00:00:38,730 18 00:00:38,730 --> 00:00:40,640 19 00:00:40,640 --> 00:00:43,170 20 00:00:43,170 --> 00:00:48,320 21 00:00:48,320 --> 00:00:52,360 22 00:00:52,360 --> 00:00:55,630 23 00:00:55,630 --> 00:01:02,430 24 00:01:02,430 --> 00:01:05,239 25 00:01:05,239 --> 00:01:06,410 26 00:01:06,410 --> 00:01:09,914 27 00:01:09,914 --> 00:01:11,330 28 00:01:11,330 --> 00:01:12,910 29 00:01:12,910 --> 00:01:14,890 30 00:01:14,890 --> 00:01:16,680 31 00:01:16,680 --> 00:01:19,750 32 00:01:19,750 --> 00:01:26,890 33 00:01:26,890 --> 00:01:31,000 34 00:01:31,000 --> 00:01:33,240 35 00:01:33,240 --> 00:01:36,526 36 00:01:36,526 --> 00:01:37,530 37 00:01:37,530 --> 00:01:42,800 38 00:01:42,800 --> 00:01:44,690 39 00:01:44,690 --> 00:01:45,460 40 00:01:45,460 --> 00:01:50,650 41 00:01:50,650 --> 00:01:54,387 42 00:01:54,387 --> 00:01:55,470 43 00:01:55,470 --> 00:01:58,930 44 00:01:58,930 --> 00:02:01,100 45 00:02:01,100 --> 00:02:02,860 46 00:02:02,860 --> 00:02:05,540 47 00:02:05,540 --> 00:02:07,660 48 00:02:07,660 --> 00:02:14,710 49 00:02:14,710 --> 00:02:16,080 50 00:02:16,080 --> 00:02:18,280 51 00:02:18,280 --> 00:02:19,530 52 00:02:19,530 --> 00:02:21,610 53 00:02:21,610 --> 00:02:23,860 54 00:02:23,860 --> 00:02:27,310 55 00:02:27,310 --> 00:02:31,830 56 00:02:31,830 --> 00:02:33,900 57 00:02:33,900 --> 00:02:35,939 58 00:02:35,939 --> 00:02:38,230 59 00:02:38,230 --> 00:02:43,940 60 00:02:43,940 --> 00:02:45,620 61 00:02:45,620 --> 00:02:48,210 62 00:02:48,210 --> 00:02:52,560 63 00:02:52,560 --> 00:02:54,570 64 00:02:54,570 --> 00:02:56,330 65 00:02:56,330 --> 00:02:58,940 66 00:02:58,940 --> 00:03:00,840 67 00:03:00,840 --> 00:03:04,610 68 00:03:04,610 --> 00:03:08,030 69 00:03:08,030 --> 00:03:10,070 70 00:03:10,070 --> 00:03:13,490 71 00:03:13,490 --> 00:03:16,930 72 00:03:16,930 --> 00:03:19,380 73 00:03:19,380 --> 00:03:22,492 74 00:03:22,492 --> 00:03:24,700 75 00:03:24,700 --> 00:03:25,740 76 00:03:25,740 --> 00:03:27,280 77 00:03:27,280 --> 00:03:30,120 78 00:03:30,120 --> 00:03:31,876 79 00:03:31,876 --> 00:03:33,250 80 00:03:33,250 --> 00:03:37,010 81 00:03:37,010 --> 00:03:39,270 82 00:03:39,270 --> 00:03:45,000 83 00:03:45,000 --> 00:03:46,900 84 00:03:46,900 --> 00:03:51,990 85 00:03:51,990 --> 00:03:54,430 86 00:03:54,430 --> 00:03:56,400 87 00:03:56,400 --> 00:04:00,560 88 00:04:00,560 --> 00:04:02,460 89 00:04:02,460 --> 00:04:05,300 90 00:04:05,300 --> 00:04:07,950 91 00:04:07,950 --> 00:04:12,110 92 00:04:12,110 --> 00:04:16,070 93 00:04:16,070 --> 00:04:17,980 94 00:04:17,980 --> 00:04:20,250 95 00:04:20,250 --> 00:04:21,990 96 00:04:21,990 --> 00:04:28,030 97 00:04:28,030 --> 00:04:30,660 98 00:04:30,660 --> 00:04:32,210 99 00:04:32,210 --> 00:04:36,420 100 00:04:36,420 --> 00:04:38,310 101 00:04:38,310 --> 00:04:41,300 102 00:04:41,300 --> 00:04:43,100 103 00:04:43,100 --> 00:04:46,280 104 00:04:46,280 --> 00:04:50,300