Sana: 201 y. Mavzu: Burchakning radian o’lchovi Darsning maqsadi

Darsning kasbga yo’naltiruvchi maqsadi: O’quvchilarga algebraic amallar orqali hisobga, arxitektura-qurilishga oid ilk tushuncha va bilimlarni singdirish.

Darsning uslubi: savol-javob, munozara.

Darsning ko’rgazmali qurollari: darslik, doska, bo’r, tarqatma materiallar, jadvallar

Darsning borishi:

Qo’shish formulalari

Qo’shish formulalari deb, cos(±) va sin(±) larni  va  burchaklarning sinus va kosinuslari orqali ifodalovchi formulalarga aytiladi.

Teorema. Ixtiyoriy  va  uchun quyidagi tenglik o’rinli bo’ladi:

cos(+)=coscos-sinsin.

Birinchi formulada  ni - ga almashtirib, hosil qilamiz:

cos(-)=coscos+sinsin.

sin(+)=sincos+cossin.

sin(-)=sincos-cossin.

Qo’shish formulalari yordamida hisoblang (325-326):

325. 1) cos135^o; 2) cos120 ^o;

3) cos150 ^o; 4) cos240 ^o.

326. 1) cos57 ^o30`cos27 <sup>o</sup>30`+sin57 ^o30`sin27 <sup>o</sup>30`;

2) cos19 ^o30`cos25 <sup>o</sup>30`-sin19 ^o30`sin25 <sup>o</sup>30`;

3)

4)

327. 1)

2)

Ifodani soddalashtiring (328-329):

328. 1) cos3cos-sinsin3; 2) cos5cos2+sin5sin2;

3)

4)

329. 1)

2)

Qo’shish formulalari yordamida hisoblang (330-331):

330. 1) sin73 ^ocos17^o+cos73^osin17^o;

2) sin73 ^ocos13 ^o-cos73 ^osin13 ^o;

3)

4)