Manyo Pak Mul...
Ikolah jawab nan sabana jawab, "instead of populun or ad verecundiam," bak kecek Sanak Ridha. Apolagi argumentum ad misericordiam. Thanks you for the right answers, Brother Ridha. Salam, ZulTan, L, Bogor Action cures fear. -----Original Message----- From: Ahmad Ridha <ahmad.ri...@gmail.com> Sender: rantaunet@googlegroups.com Date: Sun, 5 Aug 2012 10:57:47 To: <rantaunet@googlegroups.com> Reply-To: rantaunet@googlegroups.com Subject: Re: [R@ntau-Net] OOT: Matematika 64 dan 65 2012/8/4 ZulTan <zul_...@yahoo.com> > Assalamu'alaikum warahmatullaahi wabarakaatuhu, > Wa'alaykumus salaam warahmatullahi wabarakaatuh, > Problem 1: > A boat travels 12 km upstream and back in 1 hour 45 minutes. > If the speed of the current is 3 km/h throughout, find the speed of the > boat in still water, giving your answer correct to 3 significant figures. > s = 12 km t = 1.75 h 12 / (v - 3) + 12 / (v + 3) = 1.75 (12(v+3) + 12(v-3))/(v^2 - 9) = 1.75 12(v+3) + 12(v-3) - 1.75(v^2 - 9) = 0 12v + 36 + 12v - 36 - 1.75v^2 + 15.75 = 0 - 1,75v^2 + 24v + 15,75 = 0 v = 14.342 km/h > Problem 2: > A motorist makes a journey of 240 km from Singapore to Malacca to visit > his in-law at an average speed of X km/h. Write down an expression for the > number of hours taken for the journey. > t1 = 240/X hour > On his return jouney from Malacca to Singapore, his average speed is > reduced by 6 km/h due to heavy traffic at the causeway. Write down an > expression for the time taken for the return journey. > t2 = 240/(X - 6) hour > If the return journey takes 20 minutes longer, from an equation in X and > solve it to find the average speed for each journey, giving your answer > corret to two decimal places. > t2 = t1 + 1/3 hour 240/(X - 6) = 240/X + 1/3 720X - 4320 + X^2 - 6X - 720X = 0 X^2 - 6X - 4320 = 0 X = 68.80 X1 = X = 68.80 X2 = X - 6 = 62.80 Nice to have argumentation of mathematical nature, instead of ad populum and ad verecundiam ones. Thank you, Pak ZulTan. -- Abu 'Abdirrahman, Ahmad Ridha bin Zainal Arifin bin Muhammad Hamim (l. 1400 H/1980 M) -- -- . * Posting yg berasal dari Palanta RantauNet, dipublikasikan di tempat lain wajib mencantumkan sumber: ~dari Palanta R@ntauNet http://groups.google.com/group/RantauNet/~ * Isi email, menjadi tanggung jawab pengirim email. =========================================================== UNTUK DIPERHATIKAN, melanggar akan dimoderasi: - DILARANG: 1. E-mail besar dari 200KB; 2. E-mail attachment, tawarkan di sini & kirim melalui jalur pribadi; 3. One Liner. - Anggota WAJIB mematuhi peraturan serta mengirim biodata! Lihat di: http://forum.rantaunet.org/showthread.php?tid=1 - Tulis Nama, Umur & Lokasi disetiap posting - Hapus footer & seluruh bagian tdk perlu dlm melakukan reply - Untuk topik/subjek baru buat email baru, tdk mereply email lama & mengganti subjeknya. =========================================================== Berhenti, bergabung kembali, mengubah konfigurasi/setting keanggotaan di: http://groups.google.com/group/RantauNet/ -- -- . * Posting yg berasal dari Palanta RantauNet, dipublikasikan di tempat lain wajib mencantumkan sumber: ~dari Palanta R@ntauNet http://groups.google.com/group/RantauNet/~ * Isi email, menjadi tanggung jawab pengirim email. =========================================================== UNTUK DIPERHATIKAN, melanggar akan dimoderasi: - DILARANG: 1. E-mail besar dari 200KB; 2. E-mail attachment, tawarkan di sini & kirim melalui jalur pribadi; 3. One Liner. - Anggota WAJIB mematuhi peraturan serta mengirim biodata! Lihat di: http://forum.rantaunet.org/showthread.php?tid=1 - Tulis Nama, Umur & Lokasi disetiap posting - Hapus footer & seluruh bagian tdk perlu dlm melakukan reply - Untuk topik/subjek baru buat email baru, tdk mereply email lama & mengganti subjeknya. =========================================================== Berhenti, bergabung kembali, mengubah konfigurasi/setting keanggotaan di: http://groups.google.com/group/RantauNet/
