Предмет: Геометрия, автор: Милана12031

Существует ли угол:а)для которого синус равен 0,9,а косинус -0,3 в)синус-0,8, косинус-0,6

Ответы

Автор ответа: Guppy2016

0

Воспользуемся основным тригонометрическим тождеством:

$sin^2a+cos^2a=1$

Подставим значения:

Если равенство выполняется,то угол существует

Если равенство не выполняется,то угол не существует

a)

$0,9^2+(-0,3)^2=0,81+0,09=0,9$

$0,9ne1$

не существует

в)

$-0,8^2+(-0,6)^2=0,64+0,36=1$

$1=1$

существует

Предыдущий вопрос

Следующий вопрос

Интересные вопросы

Предмет: Геометрия, автор: eldarimpire

Высота СК прямоугольного треугольника АВС, проведенная к гипотенузе, делит ее на отрезки длиной 12 см и 27 см. Найдите катеты и периметр треугольника. Помогите пж срочно!!

6 лет назад

Предмет: Математика, автор: simpleboy93

ПОМОЩЬ НУЖНА ПО МАТЕШЕ

БОЯЛҒАН-?

6 лет назад

Предмет: Английский язык, автор: zhzhaksigul003

111 Choose the right variant:
What time ___ she usually go to bed?

1. do
2. is
3. dos
4. does
5. are
112 Choose the right variant:
The Bronte sisters ___ all writers.

1. was
2. were
3. is
4. does
5. am
113 Choose the right variant:
My friend bought ____ interesting book yesterday.

1. a
2. at
3. an
4. -
5. the

114 Choose the right variant:
___ a big table in the living room.

1. There are
2. There is
3. It is
4. Do
5. Does
115 Choose the right variant:
How many bedrooms ___ ?

1. there are
2. are there
3. are they
4. is they
5. is there
116 Choose the right variant:
A garage is a place ____ people fix cars.

1. which
2. who
3. whose
4. where
5. when
117 Choose the right variant:
We ___ to Istanbul three years ago.

1. go
2. is
3. went
4. goes
5. was
118 Choose the right variant:
It’s ___ to phone than to write a letter.

1. easiest
2. easy
3. easier
4. more easy
5. most easy
119 Complete the sentence:
Is there ___ in the room now?

1. somebody
2. nobody
3. anybody
4. some
5. none
120 Choose the sentence with right word order:

1. There is a nice picture over there?
2. Is there a nice picture over there?
3. A nice picture is there over there?
4. There a nice picture over there is?
5. Is a nice picture there over there?
121 Indicate the wrong sentence:

1. Is this your bag?
2. I am a student.
3. She is a secretary.
4. There are a big piano in the hall.
5. There are many children in the yard.
122 Choose the right variant:

1. The windows very dirty are.
2. The dirty windows very are.
3. The very windows dirty are.
4. The windows dirty very are.
5. The windows are very dirty.
123 Choose the right variant:
There are many ____ in my flat.

1. room
2. the rooms
3. rooms
4. rooms’
5. a room
124 Choose the right variant:
Jack London is one of ___ American writers in this country.

1. popular
2. more popular
3. the most popular
4. most popular
5. the popularest
125 Choose the right variant:
Helen is studying law ____ university.

1. at
2. of
3. on
4. –
5. for
126 Choose the right variant:
I ___ a good film on TV last night.

1. watched
2. watch
3. watches
4. watching
5. was watch
127 Choose the right variant:
My friend’s son _____ Turkish and English at university.

1. have
2. plays
3. know
4. goes
5. studies
128 Choose the right variant:
A: Do you work here?
B: Yes, I ____ .

1. work
2. do
3. am
4. don’t
5. does
129 Choose the right variant:
____ does your father do in his free time?

1. Why
2. What
3. How many
4. Where
5. What kind
130 Choose the right variant:
A: What’s the weather like in summer?
B: It’s usually hot and _____.

1. sun
2. sunny
3. sunning
4. sunnings
5. sunnies
131 Choose the right variant:
Hurry! The train leaves _____ five minutes.

1. at
2. on
3. from
4. after
5. in
132 Choose the right variant:
I ___ a bath every evening.

1. go
2. have
3. give
4. come
5. do
133 Choose the right variant:
When ___ in Los Angeles?

1. you live
2. did you lived
3. did you live
4. you live did
5. was you live
134 Choose the right form of the verb in Present Continuous Tense:
You ___ on my foot. - Oh, I am sorry!

1. was standing
2. were standing
3. am standing
4. are standing
5. is standing
135 Choose the right variant:
How much did you pay ____ those shoes?

1. in
2. at
3. for
4. till
5. by
136 Choose the right variant:
A: _____ does Anthony go to work?
B: _____ bus.

1. What / By
2. How well / On
3. What kind / In
4. How / In
5. How / By
137 Choose the right variant:

1. Have you ever been abroad?
2. Have ever you been abroad?
3. Have you been abroad ever?
4. Have you been ever abroad?
5. You been ever have abroad?

138 Choose the right variant:
What time _____ up?

1. do you usually wake
2. you usually wake
3. are you usually waking
4. usually you wake
5. usually do you wake

139 Choose the right variant:
The film has already _____.

1. start
2. starts
3. started
4. to start
5. going to start
140 Choose the right variant:
I feel fine this morning but I ___ very tired last night.

1. was
2. were
3. are
4. am
5. is
141 Choose the right form of the verb:
Life___ impossible without plants.

1. are
2. is
3. were
4. be
5. being
142 Choose the correct answer:
Му friend ____ busy yesterday.

1. were
2. was
3. is
4. are
5. has beeen
143 Find the antonym: Day

1. midday
2. night
3. month
4. year
5. week
144 Choose the right variant:
Do you know my ___ daughter?

1. uncles`
2. uncle's
3. uncless's
4. uncles
5. uncle
145 Which of the following is used with an:

1. radio
2. poem
3. boom
4. desk
5. English
146 Choose the right variant:
How many people ___ in the hotel?

1. there were
2. was there
3. were there
4. am there
5. is there
147 Choose the right variant:
___ the tickets expensive?

1. was
2. were
3. did
4. is
5. does
148 Choose the right variant:
I ___ you at the party last night.

1. didn’t saw
2. didn’t see
3. don’t saw
4. doesn’t see
5. didn’t seen
149 Choose the right variant:
I need to talk ___ the doctor.

1. up
2. from
3. in
4. of
5. to
150 Choose the right variant:
I’m coming! Wait ___ me!

1. at
2. from
3. in
4. of
5. for

6 лет назад

Предмет: Биология, автор: ильшат1

можете помочь
как происходитзаражение зерновых культур головнёвымигрибами?

9 лет назад

Предмет: Математика, автор: kristina1S

ОДНА ЧЕТВЁРТАЯ ИКС ПЛЮС ПЯТЬ ВОСЬМЫХ РАВНО ТРИ ЧЕТВЁРТЫХ

9 лет назад