用vpasolve函数可以求得:
a =0.56905902174190874945249713204175
c =0.059814651750922046381576164649624
d =9.8493426555706931819545996771277
>> syms a c d
>> [a c d]=vpasolve(25800*cos(a)+sqrt(4400^2+780^2)*cos(d)==-3400+21100*cos(c),25800*sin(a)+sqrt(4400^2+780^2)*sin(d)==10800+21100*sin(c),21100*cos(c)+17978*cos(pi-d-atan(780/4400))==35900)
验算:
>> eval(21100*cos(c)+17978*cos(pi-d-atan(780/4400)))%
ans = 35900
追问9.多弧度已经超范围了,这个问题已经解决了