1)найдите корни уравнения 4х^2 +8х-5=0 2)укажите 2 соседних целых числа, между которыми заключено число 3 корень 15 3) выражение х^2-y^2/y : x^2-xy/y и найдите его значение при x=-0,3; y=1,2 4) решите уравнение y- целых y-5/6=1
1 yesterday i had breakfast at the canteen. 2 last summer we went to the black sea. 3 he didn't call me last week. 4 why did this girl come to our office yesterday? 5 when did you buy tickets last time? 6 last june the boys played football every morning. 7 on sunday my parents were at the theatre. 8 i didn't take part at the conference last month. 9 he lived in kiev in his childhood. 10 where did he send his message? 2 трансформируйте предложения в past simplе 1 he often played chess. 2 our classes began at 9 a. m. 3 she was always busy. 4 what did you do in the evening? 5 my sister didn’t study at school, she worked at the hospital. 6 my friend prefered tea to coffee. 7 i found many stories in this magazine. 8 he was in my room, wasn't he? 9 why did you always ask so many questions? 10 jasmine seldom visited her grandparents. 3 образуйте отрицательную форму предложений 1 in summer she didn't get up early. 2 mr. white didn't write a lot of letters yesterday. 3 on friday they weren't at the station. 4 we didn't enjoy our time in rome. 5 they didn't watch a football match last weekend. 6 the girl didn't open a box at once. 7 i didn't leave my keys on the table. 8 the engineer didn't go on business trip on monday. 9 my friend didn't want to move to another flat. 10 i didn't find a surprise in the present-box. 4 поставьте вопросы к предложениям. 1 he learned english at school. (where? what language? why? or …? ) where did he learn english? what language did he learn? why did he learn english? did he learn english or french? 2 the train was five hours late. (what? why? ) what was 5 hours late? why was the train five hours late? 3 i was going to stay at my aunt’s in the crimea. (where? who? or …? ) where was i going to stay in the crimea? who was going to stay at the aunt's in the crimea? was i going to stay at my aunt's or in the hotel in the crimea? 4 they stayed in moscow only for two days. (why? where? how long? ) why did they stay in m only for 2 days? where did they stay? how long did they stay in m? 5 i bought a very beautiful dress in this shop last weekend. (where? what? when? ) where did i buy a very beautiful dress last weekend? what did i buy in this shop last weekend? when did i buy this beautiful dress in the shop? 6 they traveled to cyprus by sea. (how? where? or …? ) how did they travel to c? where did they travel to? did they travel to c or ibiza? 7 i didn’t find your telephone number. (what? why? ) what didn't i find? why didn't i find your telephone number? 8 in his childhood he was always a leader among his friends. (what? when? who? ) what was he in his childhood? when was he a leader among his friends? who was always a leader among his friends in his childhood? 9 he caught a cold last month. (what? when? why? ) what did he catch? when did he catch a cold? why did he catch a cold? 10 we did our lessons together. (what? how? ) what did we do together? how did we do our lessons?
Производная f'(x)=x²-1. Решая уравнение x²-1=0, находим 2 критические точки: x1=1 и x2=-1. При переходе через точку x2=-1 производная меняет знак с + на - , поэтому точка x2=-1 есть точка максимума, и значение функции в ней Ymax=(-1)³/3-(-1)-2=-4/3. При переходе через точку x1=1 производная меняет знак с - на + , поэтому точка x=1 есть точка минимума, и значение функции в ней Ymin=1³/3-1-2=-8/3. Но эти экстремумы - локальные, наибольшего и наименьшего значения на всей области определения, которой является вся числовая ось, данная функция не имеет. ответ: Ymax=y(-1)=-4/3,Ymin=y(1)=-8/3.
D = 64 + 80 = 144 ; √ D = 12
X1 = ( - 8 + 12 ) : 8 = 4/8 = 0,5
X2 = ( - 8 - 12 ) : 8 = - 20/8 = - 2,5
ОТВЕТ 0,5 и ( - 2,5 )
( ( X^2 - Y^2 ) / Y ) : (( X^2 - XY) / Y ) = [ ( X - Y) * ( X + Y ) ] / [ X * ( X - Y ) ] =
= ( X + Y ) / X
X = - 0,3 ; Y = 1,2
( - 0,3 + 1,2 ) / - 0,3 = 0,9 : ( - 0,3 ) = ( - 3 )
ОТВЕТ минус 3
Y - 5/6 = 1
Y = 11/6
Y = 1 ( 5/6 )