A guide to the first steps into the world of Geometry, Trigonometry and their lines-of-reasoning widely used through the high school and first years of college, in the exact-sciences context.

Elective mathematics has been an extra mathematics subject for pilot students of Eduardo Barretto Sr. National High School for quite some time now. Through this, many alumni testified how this helped them understand senior high school and college math. However, the teachers have also been struggling with the resources for specific areas of mathematics, such as Business Math, Statistics, Analytic Geometry, Trigonometry, and Calculus. When the pandemic hit the Philippines, contextualized learning material aligned with the Most Essential Learning Competencies (...) (MELC) helped elective mathematics teachers. The contextualized learning material was developed from April to August 2020 and was first validated in February 2021 by the students who participated in the pilot testing. However, following the due process, it was suggested that I revalidate the IDEA-formatted Analytic Geometry and Trigonometry instructional material. It examines Eduardo Barretto Sr. National High School mathematics teachers and SDO Calamba City experts' evaluation of the content's topics, objectives, concepts, directions, and activities and the format's prints, illustrations, design, and layout. Participants' perceptions of learning material were assessed using a 4-point Likert Scale survey. Hence, descriptive quantitative design. Participants were surveyed using a 4-point Likert Scale to assess their learning content impression. The findings reveal that the participants found the format and content of the developed learning material to be very satisfactory. The indicators "localized" and "can be done independently" were viewed as Fair and Satisfactory, respectively. The learning material was enhanced by localizing the activities and giving directions that could facilitate self-learning. (shrink)

Reviews Wildberger's account of his rational trigonometry project, which argues for a simpler way of doing trigonometry that avoids irrationals.

Trigonometry serves as an important precursor to calculus as well as college level courses. However, a possible factor that affects students from learning is teachers’ strategies in teaching. Several studies reveal that cooperative learning such as study group can increase achievement of students in mathematics. This study focused on the effects of study groups on the grade 9 students’ achievement in trigonometric problems. It sought to identify the achievement of the students in problem solving before and after the interventions (...) and to compare the interventions, the group taught with study groups and taught with the existing method. The study used true experimental design particularly pretest-posttest control group design. The study was analyzed through frequency count and percentage of scores, Wilcoxon rank test, and t-test for independents samples. The subjects of the study were the Grade 9 students in a public high school in Nueva Vizcaya, Philippines. The results revealed that majority of the students’ achievements increased. Moreover, the intervention with a study group and the existing method can improve the students’ performance in solving trigonometric problems. Furthermore, the result suggests that study group method was more effective than the existing method. (shrink)

Triangles and trigonometry are always difficult topics for both mathematics students and teachers. Hence, students' performance in solving mathematical word problems in these topics is not only a reflection of their learning outcomes but also an indication of teaching effectiveness. This case study drew from two examples of solving word problems involving triangles by pre-service mathematics teachers in a foundation mathematics course delivered by the author. The focus of this case study was on reasoning implications of students' performances on (...) the effective training of pre-service mathematics teachers, from which a three-step interactive explicit teaching-learning approach, comprising teacher-led precise and inspiring teaching (or explicit teaching), student-driven engaged learning (or imitative learning), and student-led and teacher-guided problem-solving for real-world problems or projects (or active application), was summarized. Explicit teaching establishes a solid foundation for students to further their understanding of new mathematical concepts and to conceptualize the technical processes associated with these new concepts. Imitative learning helps students build technical abilities and enhance technical efficacy by engaging in learning activities. Once these first two steps have been completed, students should have a decent understanding of new mathematical concepts and technical efficacy to analyze, formulate, and finally solve real-world applications with assistance from teachers whenever required. Specially crafted professional development should also be considered for some in-service mathematics teachers to adopt this three-step interactive teaching-learning process. (shrink)

Why All Mathematical Equations Have an Equal Sign in the Middle (Including Deviations and Applications Across All Fields of Mathematics) -/- Mathematics is a universal tool used to express relationships, patterns, and structures in both abstract and real-world settings. At the heart of this tool is the equal sign, which symbolizes balance and equivalence between two ideas. The equal sign ensures that what is expressed on one side of an equation corresponds directly to the other. However, in practical applications, perfect (...) balance is often disrupted, leading to deviations that reflect real-world imperfections. These deviations, whether positive or negative, help make mathematical models more applicable to reality. This essay explores the importance of the equal sign, the concept of deviations, and how they apply across various fields of mathematics. -/- The Equal Sign: A Symbol of Balance -/- The equal sign serves as a bridge, showing that two expressions, ideas, or quantities are equivalent. It represents the foundational principle of balance in mathematics, allowing relationships to be defined and analyzed logically. For example, when describing physical, economic, or biological systems, the equal sign provides clarity, ensuring that all components of the system interact in harmony. -/- In theory, the equal sign represents perfect balance. However, real-world scenarios rarely follow such exactitude. External factors, approximations, or errors often create deviations from this balance. These deviations allow us to account for variability and adjust our models accordingly, making mathematics a flexible tool for solving practical problems. -/- Deviations from Equality -/- While the equal sign represents the ideal state of balance, deviations account for the imperfections and complexities of reality. -/- 1. Positive Deviations: These occur when one side of a relationship exceeds the other, reflecting surplus or unexpected growth. For example, this might happen when actual outcomes surpass predictions, such as higher-than-expected profits in business. -/- 2. Negative Deviations: These arise when one side falls short, representing a deficit or shortfall. For instance, in weather modeling, negative deviations might occur when observed rainfall is less than forecasted. -/- These deviations are crucial for refining mathematical models, especially in fields where variability is unavoidable, such as physics, economics, and biology. -/- Applications in Various Fields of Mathematics -/- 1. Arithmetic and Number Theory -/- The equal sign ensures balance when performing basic operations, such as addition, subtraction, or multiplication. However, in practical applications, rounding errors or approximations often introduce deviations. For example, when adding measurements with decimals, the result might be slightly adjusted due to rounding. -/- In number theory, the equal sign represents equivalence in concepts like divisibility or patterns among numbers. Deviations can highlight remainders or shifts in these relationships, as seen in practical uses like cryptography. -/- 2. Algebra -/- Algebra explores relationships between variables and constants, often solving for unknowns. The equal sign is central to defining and solving these relationships. However, real-world algebraic problems often involve constraints or uncertainties, such as production limits in business. Deviations in algebra can account for these irregularities, making it a critical tool for optimization and resource allocation. -/- 3. Geometry -/- In geometry, the equal sign helps define relationships like the congruence of shapes, the proportions of angles, or the equivalence of areas. Deviations arise in practical applications, such as construction or design, where imperfect measurements lead to slight discrepancies. For instance, a building’s dimensions might not align perfectly with theoretical calculations due to material constraints or human error. -/- 4. Trigonometry -/- Trigonometry studies relationships in triangles and periodic phenomena, such as waves. The equal sign ensures that relationships between angles and sides are consistent. However, in fields like engineering or physics, deviations occur due to inaccuracies in measurements or environmental factors. These deviations are essential for improving real-world applications, such as signal processing or sound wave analysis. -/- 5. Calculus -/- Calculus deals with changes and accumulations. The equal sign helps express how quantities evolve or grow over time, such as the speed of an object or the amount of water collected in a tank. -/- In differential calculus, deviations reflect changes in rates caused by external influences, like friction affecting the motion of an object. -/- In integral calculus, deviations occur when real-world accumulations, such as population growth or fuel consumption, differ from idealized predictions. These adjustments make calculus more effective for analyzing and predicting real-world behavior. -/- 6. Linear Algebra -/- Linear algebra examines relationships in systems involving multiple variables, such as equations describing supply and demand. The equal sign is used to establish balance within these systems. Deviations, such as noise or inaccuracies in data, play a significant role in real-world applications like machine learning, where adjustments improve predictive accuracy. -/- 7. Probability and Statistics -/- Probability and statistics analyze uncertainty and variation. The equal sign represents theoretical models, such as the average outcome of a random event. However, deviations from these models, often referred to as errors or residuals, highlight differences between predictions and observed results. These deviations are essential for refining models, whether in weather forecasting, market analysis, or medical research. -/- 8. Real-World Modeling Across Disciplines -/- Physics: In physics, the equal sign links relationships like force and motion. Deviations arise when real-world conditions, such as air resistance, alter the ideal balance predicted by equations. -/- Economics: The concept of equilibrium in supply and demand relies on the equal sign, but market fluctuations often introduce deviations, leading to surpluses or shortages. -/- Biology: Growth models in biology, such as the spread of a population or a virus, use the equal sign to describe ideal patterns. Deviations account for environmental factors, resource limitations, or mutations. -/- Conclusion -/- The equal sign is the foundation of all mathematical equations, symbolizing balance and equivalence. It ensures that relationships are clearly defined, making mathematical reasoning precise and reliable. However, deviations play an equally important role, accounting for imperfections and variability in the real world. Across all fields of mathematics—arithmetic, algebra, geometry, calculus, and beyond—the interplay between balance and deviation enhances our ability to model, analyze, and solve complex problems. Together, the equal sign and deviations allow mathematics to bridge the gap between idealized theory and the complexities of real-world phenomena. -/- . (shrink)

● Much more relevant than the simplicity or complexity of a method of measuring the houses is whether such a division remains true to the physics of the sky (i.e. whether it makes any sense at all). ● Because astrology has no central institution to decide what is valid and what is not, we believe that the least astrologists should do is to respect the truths confirmed by science. Physics teaches that we cannot separate time from space or space from (...) time, for they stand in an unbreakable or indissoluble relationship which we call continuum , a plane made up of four dimensions (i.e. the three of space plus the one of time) regarded as spacetime, and that time is not absolute but relative (dependent on frames of reference). ● Astrology — which is not horoscopism but one of the consequences of physics — appeals to different methods of measuring segments of our horizon known as houses, sectors, or regions and has classified them into space-based measurements and time-based measurements (according to which of the two concepts decides the subdivision of the diurnal arc) , but said classification is impertinent according to the reality that governs us. ● One that can be confirmed to be compatible with our reality is to be employed at all times for all types of charts, that is to say, one that is truly or essentially spacetime-based without, at the same time, presenting any of the errors characteristic of other house systems . We will see that only one will be compatible with relativity, for while the others would have us believe that time is absolute, the Placidus method of house measurement will show us that it is relative. ● The difference lies in the ability of a method to recognise the different ascensional times of not only the twelve segments of our ecliptic at different latitudes but also of each degree of said circumference simultaneously and uninterruptedly, that is, temporally simultaneously and spatially uninterruptedly during their trajectories from the horizon (ASC) to the midheaven (MC). We concluded, based on the house cusp analysis, that only the Placidean formula can carry out this promise, that is, make it possible to measure the lengths of time under said conditions. ● While the Alcabitius and Koch measurements of time assign fictional speeds — i.e. times of oblique ascension — to all degrees contained between the horizon (ASC) and the midheaven (MC), Placidus takes care to measure the speeds or true times for all. The measurement most Newtonian of all the methods of house division, Regiomontanus, in turn, clings to space at the expense of time, the reason for which it cannot reflect the true positions of the planets in spacetime (ignores the relationship between space and time). ● During the demonstrational process, we take the opportunity of pointing out that velocity (special relativity) and gravity (general relativity) do not constitute the only — two — primary forms of time dilation. The tilt of a reference frame relative to another (that of Earth relative to the plane of our ecliptic, although velocity remains a variable, whereas gravity, in turn, a possibility we will explore in the appendices) constitutes the third form. ● We encourage any physicist and/or astronomer to corroborate our observations with their own tools. For our part, we have employed the astrological/astronomical software Solar Fire Gold, although the astrographs come from the astrological/astronomical software Janus. (shrink)