АВ перпендикулярно ВС,ВD перпендикулярно АС, точки Е и Т -середины отрезков ВD и ВС.ЕТ=8 дм, АD= 25 дм.найти ВD и tgA

 

Поставте следующие предложения в вопосительную и отрицательную формы.  1.Lectures and labotatory works are organized at university ievel.
2.Before 1970 all Oxbridge colledges were separate for men and women.
3.Only pupils who do well at A-level may go to University.
4.Universities normally select students on the basis of A-level results and interview.
5.Evry student has a tutor in charge of planning his work and discussingits results with the students.

найдите длину вектора a-b,если вектор а (11; 7),а вектор b (-4 -1)