Question

Sin3asina-cos3acosa=

Answer 1

Ответ:

Объяснение:i  Sn3asina-cos3acosa= - (cos3acosa  - Sin3asina)=-Cos (3α+α) = -Cos4α

Answer 2

To simplify the expression sin(3a) - cos(3a)cos(a), you can use trigonometric identities. First, you can expand sin(3a) using the trigonometric identity for the sine of a triple angle:

sin(3a) = 3sin(a) - 4sin^3(a).

Now, the expression becomes:

3sin(a) - 4sin^3(a) - cos(3a)cos(a).

To simplify it further, you can use the trigonometric identity for cos(3a):

cos(3a) = 4cos^3(a) - 3cos(a).

So, the expression becomes:

3sin(a) - 4sin^3(a) - (4cos^3(a) - 3cos(a))cos(a).

Now, distribute the -cos(a) through the expression:

3sin(a) - 4sin^3(a) - 4cos^4(a) + 3cos^2(a).

Now, you have a trigonometric expression in terms of both sine and cosine. Depending on what you need to do with this expression, you might be able to simplify it further or leave it in this form.