Understand Cosine Function Behavior: We need to understand the behavior of the cosine function to determine the range of f(x). The cosine function, cos(θ), has a range of [−1,1] for any real number θ.
Consider Argument of f(x): Now, let's consider the argument of the cosine function in f(x), which is ex–sin(x). The exponential function ex is always positive for all real x, and sin(x) oscillates between −1 and 1.
Positivity of ex−sin(x): Since ex is always greater than sin(x), the expression ex–sin(x) will always be positive.However, the exact value of ex–sin(x) can vary greatly depending on x.
Cosine Range Constraint: Regardless of the value of ex−sin(x), the cosine of this expression will always fall within the range of the cosine function itself, which is [−1,1].
Final Range of f(x): Therefore, the range of f(x)=cos[ex–sin(x)] is the same as the range of the cosine function.The range of f(x) is [−1,1].
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