Question

1)cos63° cos18° + sin 63° sin 18°

Answer 1

Ответ:

=cos(63°- 18°)=cos45°=sqrt{2} /2[/tex]

Пошаговое объяснение:

Answer 2

To simplify the expression, we can use the trigonometric identity for the cosine of the sum of two angles:

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

where A = 63° and B = 18°. Let's plug in the values:

cos(63° + 18°) = cos 63° * cos 18° - sin 63° * sin 18°

Now, we have the expression in terms of cosines of individual angles. We know that:

cos(63° + 18°) = cos 81°

So, the simplified expression is:

cos 81°

You can use a calculator to find the value of cos 81°, which is approximately 0.154251.