如何找到以度为单位的反余弦 java

Question

我只是想做一个包罗万象的计算器，但我运行遇到了问题。当我试图使用余弦定律找到缺失的角度时，我得到的答案与我的计算器不一样。

double answer = 0;
else if (solver == 2 && choice == 2)
    {
        System.out.println("Enter side length opposite of wanted angle: ");
        double c = in.nextDouble();
        System.out.println("Enter known side #2: ");
        double b = in.nextDouble();
        System.out.println("Enter known side #3: ");
        double a = in.nextDouble();

        answer = (Math.pow(c, 2) - Math.pow(b,2) - Math.pow(a,2)) /  (-2 *         (a * b));
        answer = Math.acos(answer);
        System.out.println("Answer: " + answer);
    }

没有 "answer = Math.acos(answer);"，我在最后一步之前得到了所需的正确答案，但随后我需要该答案的反余弦值。我没有得到正确的答案。有人明白为什么吗？

Answer 1

这给了我正确的输出，注意添加了 Math.toDegrees():

        double answer = (Math.pow(c, 2) - Math.pow(b,2) - Math.pow(a,2)) / (-2 * (a * b));
        answer = Math.acos(answer);
        System.out.println("Answer: " + Math.toDegrees(answer));

如何找到以度为单位的反余弦 java

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