Қосу формулалары. Алгебра, 9 сынып, қосымша материал.

 Үйге тапсырма

№ 498.

• cos (= cos cosα – sin sinα = cosα – sinα
• sin(= sin cosα – cos sinα = cosα – sinα

№ 499.

1. sin150⁰= sin(⁰+60⁰)= sin90⁰ cos60⁰ + cos 90⁰ sin60⁰ =1 +0 =

2.cos150⁰= cos(⁰+60⁰)=cos90⁰ cos60⁰ – sin90⁰ sin60⁰=0 =

№ 501.

cos103⁰ cos13⁰ + sin103⁰ sinβ13⁰ =cos(103⁰ – 13⁰)=cos 90⁰ =0

cos15⁰ cos30⁰ – sin30⁰ sinβ15⁰ =cos(15⁰ + 30⁰)=cos 45⁰ =

sin51⁰ cos39⁰ + cos51⁰ sin39⁰=sin(51⁰+39⁰)=sin90⁰=1

sin63⁰ cos33⁰ – cos63⁰ sin33⁰=sin(63⁰+33⁰)=sin30⁰=

 Үйге тапсырма

№ 498.

• cos (= cos cosα – sin sinα = cosα – sinα
• sin(= sin cosα – cos sinα = cosα – sinα

№ 499.

1. sin150⁰= sin(⁰+60⁰)= sin90⁰ cos60⁰ + cos 90⁰ sin60⁰ =1 +0 =

2.cos150⁰= cos(⁰+60⁰)=cos90⁰ cos60⁰ – sin90⁰ sin60⁰=0 =

№ 501.

cos103⁰ cos13⁰ + sin103⁰ sinβ13⁰ =cos(103⁰ – 13⁰)=cos 90⁰ =0

cos15⁰ cos30⁰ – sin30⁰ sinβ15⁰ =cos(15⁰ + 30⁰)=cos 45⁰ =

sin51⁰ cos39⁰ + cos51⁰ sin39⁰=sin(51⁰+39⁰)=sin90⁰=1

sin63⁰ cos33⁰ – cos63⁰ sin33⁰=sin(63⁰+33⁰)=sin30⁰=