Peningkatan Kemampuan Pemecahan Masalah pada Materi Persamaan Garis Singgung Lingkaran melalui Pembelajaran Discovery Learning

This study aimed to improve student’s problem-solving abilities of tangent circle equations using discovery learning. This research was done in class XI IPA 4 SMA N 1 Palembang. This research method is used Classroom Action Research with discovery learning models. The instrument is used test instrument in the form of an evaluating matter of the tangent circle equation in the description form and the observation sheet for observation of the learning activity of the students. The results of the study showed that there is an increase in students' problem-solving abilities in tangent circle equation material using discovery learning. This increase can be seen from the results of the post-test students with an average score of 93,6 which increased when compared with the results of the pre-test with an average value of 58,2. The percentage of students who complete learning increases from 30% pre-test to 100% at post-test with KKM (maximum mastery criteria) ≥ 70. Based on the data analysis, it can be concluded that learning with discovery learning models can improve student learning outcomes in the tangent of circle equation material.

ANALYSIS OF MATHEMATICAL COMMUNICATION ABILITY AND SELF REGULATED LEARNING MATHEMATICS STUDENT’S OF CLASS IX SMP NEGERI 2 CILAMAYA KULON

This study aims to determine mathematical communication ability and self-regulated learning mathematics of IX grade students of SMP Negeri 2 Cilamaya Kulon Karawang on circle material and circle tangents. This research is a qualitative descriptive study, where the object of research is class IX students as many as 35 students. This research was conducted on November 20, 2018. The research technique was in the form of a test of 6 items test questions of mathematical and non-test communication ability in the form of a questionnaire with 40 items of self regulated learning mathematical statements and interviews. The results of this study are mathematical communication ability of students classified as moderate with a reliability coefficient of 0.9793 (very high category), having a mean difficulty index of 0.539 (medium category), and a mean differentiation of 0.485 (good category). Student constraints when working on mathematical communication problems on circle material and tangent circle are students who are less able to analyze the core of the problem, students do not understand the form of non-routine questions (mathematical communication), students are confused in determining completion strategies, students cannot visualization, students do not know the terms in mathematics, as well as procedural errors in progress. While for self regulated mathematics students have a good category.

Analysis of Students Misconception in Completing Mathematical Questions Using Certainty of Response Index (CRI)

The misconception is a notion of an understanding that is inconsistent with a scientific notion or an interpretation of the relationship of unacceptable concepts. This study conducted to identify the misconception of students of class VIII MTs Negeri 9 Cirebon on the concept of a tangent circle. The research method used is a mixed method. Sampling using random sampling, so that obtained 48 student samples. The instruments used in this study were multiple choice objective tests accompanied by Certainty of Response Index (CRI) method and diagnosis interview. Based on its completeness, the analysis shows that misconceptions appear on sub concepts tangent of the circle of 34,5%, a tangent to two circles of 35,6%, an outer circle and an inner circle of the triangle of 33,3%. On average misconceptions that occur in students that are at sub concepts, tangent two circles on about ten percentage are 43,8%. This analysis shows that misconceptions in the student because students do not understand the concept fully and connecting one concept to another with partial understanding, resulting in the student, makes the wrong conclusions. Based on analysis of these data showed that the CRI effectively used to determine the misconceptions and effective diagnostic interview used in knowing the reason students are causing students had misconceptions.

PENINGKATAN PENGUASAAN KONSEP GARIS SINGGUNG LINGKARAN DENGAN METODE PENEMUAN TERBIMBING BERKELOMPOK PADA PROGRAM STUDI PENDIDIKAN MATEMATIKA UM MATARAM

Abstrak:Salah satu kesulitan mahasiswa dalam mata kuliah geometri analitik bidang adalah memecahkan masalah tentang garis singgung lingkaran jika dikaitkan dengan kehidupan sehari-hari. Kesulitan ini dapat disebabkan karena kurangnya pemahaman terhadap konsep garis singgung lingkaran. Pembelajaran matematika dengan metode penemuan merupakan satu komponen penting dalam pandangan konstruktivis dimana pengetahuan dibentuk oleh mahasiswa sendiri secara aktif, kemudian disimpan sebagai suatu susunan atau struktur pengetahuan yang saling terkait satu sama lain seperti jaring laba-laba dantidak hanya sekedar bersifat hirarkis. Mahasiswa secara aktif baik fisik (bekerja) maupun mental (berpikir) dalam membentuk pengetahuannya sendiri. Penelitian yang dilakukan merupakan penelitian tindakan kelas yang bertujuan untuk memperbaiki kinerja dosen sehingga dapat meningkatkan pemahaman siswa dalam menguasai suatu mata kuliah. Sumber data dalam penelitian ini adalah semester IV jurusan pendidikan matematika FKIP UM Mataram. Sedangkan mahasiswa yang diambil sebagai subjek untuk wawancara adalah 4 mahasiswa dengan pertimbangan agar memudahkan fokus perhatian dan pengamatan sehingga mencapai refleksi mendalam. Pemilihan subjek untuk wawancara ditentukan berdasarkan pada hasil tes awal. Keempat mahasiswa ini terdiri dari 1 mahasiswa berkemampuan tinggi, 2 mahasiswa berkemampuan sedang, dan 1 mahasiswaberkemampuan rendah. Setelah dataterkumpul, maka data perlu segera dianalisis. Analisisdata yang dilakukan dalam penelitian ini adalah analisisdata kualitatif dan kuantitatif. Data ini dianalisis dengan langkah-langkah sebagai berikut: (1) mereduksi data,(2) menyajikan data, dan (3) menarik kesimpulan serta verifikasi. Berdasarkan tujuan penelitian dan hasil penelitian dapat disimpulkan bahwa penerapan metode penemuan terbimbing berkelompok dapat meningkatkan penguasaan konsep garis singgung lingkaran pada matakuliah geometri analitik di jurusan pendidikan matematika UM Mataram.Hal tersebut terbukti dengan meningkatnya nilai rata-rata mahasiswa dan meningkatnya SR yang dihasilkan jika membenadingkan hasil tes awal dan tes akhir. Abstract: One of the student difficulties in the field of analytical geometry is to solve the problem of tangent circles when associated with daily life. This difficulty can be caused by a lack of understanding of the concept of tangent circles. Mathematical learning by discovery method is an important component in constructivist view where knowledge is actively shaped by the students themselves, then stored as a structure or knowledge structure interconnected with each other like spider webs and not just hierarchical. Students are both physically active (working) and mental (thinking) in shaping their own knowledge. The research conducted is a classroom action research that aims to improve the performance of lecturers so as to improve students' understanding in mastering a course. Sources of data in this study is the fourth semester majoring in mathematics education FKIP UM Mataram. While the students are taken as the subject for the interview is 4 students with consideration to facilitate the focus of attention and observation so as to achieve deep reflection. The subject selection for the interview is determined based on the initial test results. The four students consist of 1 high-ability student, 2 medium-skilled students, and 1 low-skilled student. After the data gathered, then the data needs to be analyzed immediately. Data analysis conducted in this research is qualitative and quantitative data analysis. This data is analyzed by the following steps: (1) reducing data, (2) presenting data, and (3) drawing conclusions and verification. Based on research objectives and research results can be concluded that the application of guided discovery method can improve the mastery of the concept of tangent circle in the analytic geometry course in the majors of mathematics education UM Mataram.Hal is evidenced by the increase in the average value of students and the increase in SR generated if membenadingkan results preliminary and final tests.

Theoretical Analysis on Manufacturing Hypoid Left-Hand Gears by Generating-Line Method

According to the hypoid gear tooth surface forming principle, a generating-line will be formed in round-plane while a cone and its tangent circle plane do pure rolling, and the hypoid gear is cutting according to the motion equation as hypoid gears generating-line. to tools shape. The milling processing equation of the hypoid left-hand gear tooth surface on the right side gear tooth surface and on the left side gear tooth surface.There are a detailed description of the adjusting-tool , cutting out from ends, dividing, cycle cutting the whole process. The above method can realizes hypoid gearwheel right tooth surface processing.