Question

Cos72cos12 + sin12sin72

Answer 1

Ответ:

1/2

Объяснение:

cos72°cos12° + sin12°sin72°=cos(72°-12°)=cos60°=1/2

Answer 2

Ответ:

$\frac{1}{2}$

Объяснение:

Формула косинуса разности: $cos(\alpha-\beta)=cos\alpha cos\beta+sin\alpha sin\beta$

$cos72^ocos12^o+sin12^osin72^o=cos(72^o-12^o)=cos60^o=\frac{1}{2}$

Answer 3

To simplify the expression cos(72)cos(12) + sin(12)sin(72), we can use the trigonometric identity for the cosine of the difference of angles:

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

By substituting A = 72 and B = 12, we can rewrite the expression as:

cos(72 - 12)

Now, 72 - 12 = 60, so the expression simplifies to:

cos(60)

Since the cosine of 60 degrees is equal to 0.5, the simplified expression is:

0.5