Xalqaro Nordik universiteti iqtisodiyot fakulteti 1-eks-22 guruh

Yig‘indi va ayirma formulalari:
kosinuslar har doim "juft bo'lib ketadi". Ikkita kosinus - "bulochka" qo'shib, biz bir juft kosinus - "koloboks" ni olamiz. Va ayirish, biz, albatta, koloboklarni olmaymiz. Biz bir nechta sinuslarni olamiz. Oldinda hali minus.
Sinuslar - "aralash" :

Yig’indilarga doir misollar

Yig’indilarga doir misollar

1-Misol.

Yechish:

cos15=cos(45-30) ekanligidan va cosinus uchun

qo’shish formulasidan foydalansak

Cos(45-30)=cos45

= +

Javob:

+

•  

2-Misol. Cos()Cos() - sin ()sin () ni hisoblang

2-Misol. Cos()Cos() - sin ()sin () ni hisoblang

Yechish:

Cosinus uchun cos( formuladan foydalansak

Cos()Cos() - sin ()sin ()

Cos()

cos

Javob:

-1

•  

3-Misol. Sin( ni hisoblang

3-Misol. Sin( ni hisoblang

Yechish:

Sinus uchun sin(=sin cos+ cos formuladan foydalansak

Sin(

sin cos + cos -

sin cos bo’ladi

Javob:

sin cos

•  

4-Misol. Sin5x cos3x – cos5x sin3x ni hisoblang

4-Misol. Sin5x cos3x – cos5x sin3x ni hisoblang

Yechish:

Sinus uchun sin (=sin sin

Formuladan foydalansak

Sin5x cos3x – cos5x sin3x

Sin(5x-3x)

Sin2x

Javob:

2x

•  

5-Misol. Agar cost=- va bo’lsa, sin( +t) ni hisoblang

5-Misol. Agar cost=- va bo’lsa, sin( +t) ni hisoblang

Yechish:

Birinchi navbatda burchakning qaysi chorakka tegishli ekanligini aniqlab olamiz, cost=- dan sint= kelib chiqadi.

sin ( +t) =sin ()+ cos () sint

(- )+ = -

Javob:

-

•