Final answer:
The value of x in the given trigonometric expression cannot be uniquely determined without additional information or equations. The expression alone does not allow for solving for a unique value for x.
Step-by-step explanation:
To find the value of x in the expression sin(4x - 10°) · cos(40° - x), we must recognize that we are dealing with a simple trigonometric function and not an equation or inequality that can be solved for a specific number. The expression is a product of a sine and cosine function with different angles, and without additional equations or information, we cannot determine a unique value for x just based on this expression alone. Therefore, there might be a misunderstanding of the question as presented.
If the original problem involves equating the expression to a specific value and solving for x, then we would use trigonometric identities or algebraic methods to find the solution. However, with the information provided, no unique value for x can be determined, and we can not choose from the options a) 0 b) 1 c) 2 d) 3.