cos2x+cos3x +cos4x/sin2x+2sin3x+sin4x=ctg3x пожалуйста помогите

cos2x+cos3x +cos4x/sin2x+2sin3x+sin4x=ctg3x пожалуйста помогите
- Предмет:
  Алгебра
- Автор:
  ian5rcs
- 6 лет назад

Ответы 1

cosa+cosb=2cos[(a+b)/2]*cos[(a-b)/2]sina+sinb=2sin[(a+b)/2]*cos[(a-b)/2]----------------------------------------------------(в примере должно быть либо 2cos3x ,либо sin3x -опечатка(cos2x+2cos3x+cos4x)/(sin2x+2sin3x+sin4x)==(2cos3xcosx+cos3x)/(2sin3x*cosx+2sin3x)==2cos3x*(cosx+1)/2sin3x(cosx+1)=сtg3x
- Автор:
  ceceliaqxtb
- 6 лет назад
- 0
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The architect usually begins to work when the site type and cost of a building have been determined.
Planning the environment. The natural environment is at once a hindrance and a help, and the architect seeks both to invite its aid and to repel its attacks. To make buildings habitable and comfortable, he must control the effects of heat, cold, light, air, moisture, and dryness and foresee destructive potentialities such as fire, earthquake, flood, and disease.
The placement and form of buildings in relation to their sites, the distribution of spaces within buildings, and other planning devices discussed below are fundamental elements in the aesthetics of architecture.
Orientation. The arrangement of the axes of buildings and their parts is a device for controlling the effects of sun, wind, and rainfall.
Within buildings, the axis and placement of each space determine the amount of sun it receives. Orientation may control air for circulation and reduce the disadvantages of wind, rain, and snow.
The characteristics of the immediate environment also influence orientation: trees, land formation, and other buildings create shade and reduce or intensify wind, while bodies of water produce moisture and reflect the sun.
Architectural forms. Planning may control the environment by the design of architectural forms that may modify the effects of natural forces.
Colour. Colour has a practical planning function as well as an expressive quality because of the range of its reflection and its absorption of solar rays. Since light colours reflect heat and dark colours absorb it, the choice of materials and pigments is an effective tool of environmental control.
Materials and techniques. The choice of materials is conditioned by their own ability to withstand the environment as well as by properties that make them useful to human beings. One of the architect's jobs is to find a successful solution to both conditions; to balance the physical and economic advantages of wood against the possibility of fire, termites,, and mold, the weather resistance of glass and light metals against their high thermal conductivity, and many similar conflicts.
Interior control. The control of the environment through the design of the plan and the outer shell of a building cannot be complete, since extremes of heat and cold, light, and sounds penetrate into the interior, where they can be further modified by the planning of spaces and by special conditioning devices.
Temperature, light and sound are all subject to control by the size and shape of interior spaces, the way in which the spaces are connected, and the materials employed for floors, walls, ceilings, and furnishings.
Today, heating, insulation, air conditioning, lighting, and acoustical methods have become basic parts of the architectural program.
Planning for use. While environmental planning produces comfort for the senses (sight, feeling, hearing) and reflexes (respiration), planning for use or function is concerned with convenience of movement and rest.
Differentiation. The number of functions requiring distinct kinds of space within a building depends not only upon the type of building but also upon the requirements of the culture and the habits and activities of the individual patrons. A primitive house has a single room with a hearth area, and a modern one has a separate areas for cooking, eating, sleeping, washing, storage, and recreation.
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cos2x+cos3x +cos4x/sin2x+2sin3x+sin4x=ctg3x пожалуйста помогите

Ответы 1

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