Question

Cos76*cos16+sin76*sin16 ?

Answer 1

Есть такая формула
 Cos x * Cos y + Sin y * Sin x = Cos(x-y)

Cos76*cos16+sin76*sin16= Cos(76-16)=Cos 60=  $\frac{1}{2}$=0.5

Answer 2

To evaluate the expression cos(76)*cos(16) + sin(76)*sin(16), you can use the trigonometric identity known as the cosine of the difference of angles:

cos(a - b) = cos(a)*cos(b) + sin(a)*sin(b)

In this case, a = 76 and b = 16. Using the identity, we can rewrite the expression as:

cos(76 - 16)

Now, calculating the angle:

76 - 16 = 60

So the expression simplifies to:

cos(60)

The cosine of 60 degrees is equal to 0.5.

Therefore, cos(76)*cos(16) + sin(76)*sin(16) = 0.5.