Question

Sin 21 cos 9 + cos 21 sin 9

Answer 1

Ответ: sin(21+9), по формуле, ответ sin(30), если в градусах, то ответ 1/2

Объяснение:

Answer 2

Ответ:

sin 21 cos 9 + cos 21 sin 9 = sin 30

Answer 3

To calculate the value of the expression sin(21)cos(9) + cos(21)sin(9), you can use the trigonometric identity for the sum of angles:

sin(A + B) = sin(A)cos(B) + cos(A)sin(B)

Using this identity, the given expression becomes:

sin(21 + 9) = sin(30)

Since sin(30) = 1/2, the final result is:

sin(21)cos(9) + cos(21)sin(9) = 1/2