Question

Cos 11p/60*cos 3p/20 - sin 11p/60 *sin 3p/20​

Answer 1

Ответ:

Пошаговое объяснение:

1) упростить  выражение, используя cos (t) * cos (s) - sin (t) * sin (s) = cos(t+s):

=cos(11п/60 + 3п/20) = cos(п/3)

2) вычислить выражение, используя таблицу значений тригонометрических функций:

=1/2

Ответ: 1/2

Answer 2

The expression you've provided is a trigonometric expression involving cosine and sine functions. Let's break it down step by step:

cos(11p/60) * cos(3p/20) - sin(11p/60) * sin(3p/20)

We can simplify this expression using the trigonometric identity: cos(a - b) = cos(a) * cos(b) + sin(a) * sin(b).

In our case, a = 11p/60 and b = 3p/20.

cos(11p/60) * cos(3p/20) - sin(11p/60) * sin(3p/20) = cos(11p/60 - 3p/20)

Now, let's find the common denominator for 60 and 20, which is 60.

= cos((11p * 20 - 3p * 60)/(60 * 20)) = cos((220p - 180p)/(1200)) = cos(40p/1200) = cos(p/30)

So, the simplified form of the expression cos(11p/60) * cos(3p/20) - sin(11p/60) * sin(3p/20) is cos(p/30).