我先用solve解的 我最终想得到的是角度所以用了Degree
Solve[-2.88 Sin[x Degree ]*Sin[x Degree] - 3.026 Cos[x Degree]*Cos[x Degree] + 9.667 Cos[x Degree ] + 9.356 Sin[x Degree ] + 0.068 Sin[x Degree ]*Cos[x Degree] - 0.436 == 0, x]
解出来得到了四个解
{{x -> -69.1972 - 293.326 I}, {x -> -69.1972 + 293.326 I}, {x -> -31.0633}, {x -> 119.51}} 有两个貌似是虚数
结果就提示我
Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; use Reduce for complete solution information.
然后我就用了约化reduce
Reduce[-2.88 Sin[x Degree ]*Sin[x Degree] - 3.026 Cos[x Degree]*Cos[x Degree] + 9.667 Cos[x Degree ] + 9.356 Sin[x Degree ] + 0.068 Sin[x Degree ]*Cos[x Degree] - 0.436 == 0, x]
结果也得到了四个解
C[1] \[Element] Integers && (x == 57.2958 (-0.542156 + 6.28319 C[1]) || x == 57.2958 (2.08584 + 6.28319 C[1]) || x == 57.2958 ((-1.20772 - 5.11951 I) + 6.28319 C[1]) || x == 57.2958 ((-1.20772 + 5.11951 I) + 6.28319 C[1]))
结果提示我Reduce::ratnz: Reduce was unable to solve the system with inexact coefficients. The answer was obtained by solving a corresponding exact system and numericizing the result.
我的问题最主要是 能不能Solve得到的解和Reduce得到的解能不能等价呢 按照题目规定的条件x是实数 且为正数 所以就直接舍去了 其他三个 那剩下的一个 我应该用Reduce的还是solve的 或者说我这个方法是不是错了
跪求大神解答!!!

1 方法没错
2 两次的解实际上是等价的,用哪个都可以
3 第一次的解实际上就是第二次解的重新排列,对应关系为
x == 57.2958 (-0.542156 + 6.28319 C[1]) <==> x -> -31.0633
x == 57.2958 (2.08584 + 6.28319 C[1]) <==> x -> 119.51
x == 57.2958 ((-1.20772 - 5.11951 I) + 6.28319 C[1]) <==> x -> -69.1972 - 293.326 I
x == 57.2958 ((-1.20772 + 5.11951 I) + 6.28319 C[1]) <==> x -> -69.1972 + 293.326 I
实际上把括号展开就很明显了
x == 57.2958 (-0.542156 + 6.28319 C[1]) =-31.0633+ 360C[1], C[1]是整数,这个360就相当于2π