Question

Cos 20+ sin 20 / cos 40

Answer 1

Ответ:

Объяснение:

2 Cos20 * Cos40 - Cos20=  

Используем формулу  

Cosα * Cosβ=(1/2)*( Cos(α-β)+ Cos(α+β))  

=2 *(1/2)*( Cos(20-40)+ Cos(20+40))- Cos20=1*(Cos(-20)+ Cos60)- Cos20=  

Используем формулу  

Cos(-α)= Cosα, получим  

= Cos20+ Cos60- Cos20= Cos60=1/2=0,5

Answer 2

To evaluate the expression cos 20 + sin 20 / cos 40, we'll break it down into two parts: cos 20 and sin 20 / cos 40.

First, let's calculate cos 20:

cos 20 ≈ 0.9397

Now, let's calculate sin 20 / cos 40:

sin 20 ≈ 0.3420 cos 40 ≈ 0.7660

sin 20 / cos 40 ≈ 0.3420 / 0.7660 ≈ 0.4462

Finally, let's substitute these values back into the original expression:

cos 20 + sin 20 / cos 40 ≈ 0.9397 + 0.4462 ≈ 1.3859

Therefore, cos 20 + sin 20 / cos 40 is approximately equal to 1.3859.