第2章方程式と不等式Equations and Inequalities

Introduction to Equations and Inequalities方程式と不等式のはじめに

An aerial view of more than twenty circular crop fields of different sizes. Their varying colors indicate different crops or growing patterns. — From the air, a landscape of circular crop fields may seem random, but they are laid out and irrigated very precisely. Farmers and irrigation providers combining agricultural science, engineering, and mathematics to achieve the most productive and efficient array. (Credit: Modification of "Aerial Phot of Center Pivot Irrigations Systems (1)" by Soil Science/flickr)空から見ると、円形の畑が並ぶ風景は行き当たりばったりに見えるかもしれないが、これらはきわめて正確に配置され、水を引かれている。農家と灌漑の業者は、農学・工学・数学を組み合わせて、いちばん実りが多く無駄のない並べ方を作り出している。(出典: Soil Science/flickr の "Aerial Phot of Center Pivot Irrigations Systems (1)" を改変)

• 2.1 The Rectangular Coordinate Systems and Graphs • 2.2 Linear Equations in One Variable • 2.3 Models and Applications • 2.4 Complex Numbers • 2.5 Quadratic Equations • 2.6 Other Types of Equations • 2.7 Linear Inequalities and Absolute Value Inequalities

・2.1 直交座標系とグラフ・2.2 一元一次方程式・2.3 モデルと応用・2.4 複素数・2.5 二次方程式・2.6 その他の方程式・2.7 一次不等式と絶対値を含む不等式

Irrigation is a critical aspect of agriculture, which can expand the yield of farms and enable farming in areas not naturally viable for crops. But the materials, equipment, and the water itself are expensive and complex. To be efficient and productive, farm owners and irrigation specialists must carefully lay out the network of pipes, pumps, and related equipment. The available land can be divided into regular portions (similar to a grid), and the different sizes of irrigation systems and conduits can be installed within the plotted area.

灌漑は農業を支える重要な技術である。収穫量を増やし、自然の条件だけでは作物を育てにくい土地でも耕作を可能にする。その一方で、資材・設備・水には費用がかかり、設備の構成も複雑になる。農場主や灌漑の専門家は、効率よく作物を育てるため、配管・ポンプ・関連設備を適切に配置しなければならない。土地を格子状の規則的な区画に分ければ、その区画に合わせて、さまざまな大きさの灌漑装置や導水管を設置できる。