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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def annealing_cos(start:Number, end:Number, pct:float)->Number:
    "Cosine anneal from `start` to `end` as pct goes from 0.0 to 1.0."
    cos_out = np.cos(np.pi * pct) + 1
    return end + (start-end)/2 * cos_out