Final answer:
The question involves simplifying a trigonometric expression using a double-angle or half-angle formula, which falls under the Mathematics subject and is typically taught at the High School level.
The correct option is A.
Step-by-step explanation:
The question at hand involves simplifying an expression using either a double-angle formula or a half-angle formula. These formulas are part of trigonometry, a branch of Mathematics that deals with the relationships between side lengths and angles of triangles.
As such, options relating to quadratic equations, exponential functions, or logarithmic expressions are not directly relevant unless they are part of the trigonometric simplification process.
To simplify a trigonometric expression using a double-angle or half-angle formula, you would typically identify if the expression can be rewritten using identities such as sin(2x) = 2sin(x)cos(x) or cos(2x) = cos2(x) - sin2(x) for double angles, or sin(x/2) = ±sqrt((1 - cos(x))/2) or cos(x/2) = ±sqrt((1 + cos(x))/2) for half angles.
These transformations are used to simplify complex trigonometric equations into more manageable forms.
When dealing with mathematical relationships, such as the rate law in Chemistry, understanding the principles of exponential growth or logarithmic functions can help in solving for unknown variables. In physics, equations need to be dimensionally consistent, which means that all terms within an equation must be dimensionally equivalent.
The correct option is A.