Matlab出现is not a valid expression or equation.clear;syms theta x;solve('9.8*x*x/(tan(theta)*tan(theta))-(2*240000*(sqrt(7)-sqrt(4*cos(theta)+5))-196*(25+100)*(sin(theta)-sqrt(3)/2))*x/((1/3*5+100)*tan(theta))+9.8*x*x-2*10*sin(theta)*(240000*(sqrt