Solve Equation(a) LI² + RI + 1/C = 0 for I(b) (x-h)² + (y-k)² = r² for y

matlab Error using ==> solve is not a valid expression or equation.syms x l r n b kf1=('cos(pi/2-l/bn)=(r.^2+(x+sqrt(k.^2-r.^2)).^2-k.^2)/(2*r*(x+sqrt(k.^2-r.^2)))');[a]=solve(f1)Error using ==> solve' cos(pi/2-l/bn)=(r.^2+(x+sqrt(k.^2-r.^2)).^2-k.^2 Hence by using a suitable substitution ,solve the equation 25^2(5x+3)=50x+24 solve the equation 49-81x=0 matlab solve x./(x.^2+10)=0.1581 ' is not a valid expression or equation.提示我这个,我这个方程哪里错了? solve the equation 2x^2-4x=-3 and express the roots in a+bi form.太久没做了,忘记怎么算了. Solve Equation(a) LI² + RI + 1/C = 0 for I(b) (x-h)² + (y-k)² = r² for y Equation solve the equation .solve the equation 2x³-3x²-11x+6=0 given that -2 is a zero of f(x)=2x³-3x²-11x+6.要翻译和解题过程 matlab代码哪里有错啊?> [a,b,] = solve('(1+b(5/18-a)^(-2))^(-1)=0.9','(1/1+b(0-a)^(-2))=0)^(-1)','a','b')Error using solve>processString (line 354)' (1/1+b(0-a)^(-2))=0)^(-1) ' is not a valid expression or equation.Error in solve>getEqns (line 谁可以帮我看看这几题呢?solve each equation by factoring.(我会谁可以帮我看看这几题呢?solve each equation by factoring. (我会采纳的!) matlab解方程老出现is not a valid expression or equation.clear;clc;clf;syms x K R L D T Iref E a tao;K=0.3;R=10;L=12e-3;D=0.4;Iref=5;T=1e-4;E=350;a=E/R;tao=L/R;x=solve('(x-a)*exp(-T/tao)+2*a*exp((-T/tao)*(1-D-K*(Iref-x)))-a-x=0','x')出现错误 求论文A non standard multigrid method with flexible multiple semi coarsening for the numerical……A non standard multigrid method with flexible multiple semi coarsening for the numerical solution of the pressure equation in a Navier-Stokes solve solve a differential equation!In a hurryy''-2y'+y=e^t * t^-1特解怎么求？是设 特解u= A* t*e^t*(In t- B),然后带入求得常数ab 值得？ How to solve The number of real solution to the equation x/sinx=100 is Solve the equation cosx= -0.4 on the interval 0≤x＜2π. 常微分solve the equation(x+4y)y'=2x+3y+5 the problem solve itThe tangent line to a circle may be defined as the line that intersects the circle in a single point,called the point of tangency.If the equation if the circle is x^2 + y^2 = r^2 and the equation of the tangent line is y = mx + b, solve a crime