学习率影响

def solve():
    import matplotlib.pyplot as plt
    def loss(____):
        return x**____
    def gradient(____):
        return ____*x
    learning_rates = [____, ____, ____, ____]
    plt.figure(figsize=(____, ____))
    for lr in learning_rates:
        x = ____
        history = [x]
        for _ in range(____):
            x = x - lr * gradient(____)
            history.append(____)
        plt.plot(____)
    plt.xlabel(____)
    plt.ylabel(____)
    plt.title(____)
    plt.legend()
    plt.grid(____)
    plt.show()