how to solve these equations

hi, everyone

i wanna find a specific answer for these equations :

a^2+b*c==-1

,a*b+b*d==1,

a*c+c*d==-1,

d^2+b*c==0

which matlab function can i use to solve the equations above?

btw ,without using matlab , how can i solve it?

Answer 1

[Stephan]

for only real solutions:

syms a b c d real
eq(1) = a^2+b*c==-1;
eq(2) = a*b+b*d==1;
eq(3) = a*c+c*d==-1;
eq(4) = d^2+b*c==0;
res = solve(eq);
res_a = res.a
res_b = res.b
res_c = res.c
res_d = res.d

otherwise, if complex solutions are also needed:

syms a b c d
eq(1) = a^2+b*c==-1;
eq(2) = a*b+b*d==1;
eq(3) = a*c+c*d==-1;
eq(4) = d^2+b*c==0;
res = solve(eq);
res_a = res.a
res_b = res.b
res_c = res.c
res_d = res.d

Answer 2

[Star Strider]

You already formatted them to work with the Symbolic Math Toolbox (unless the ‘==’ means a logical operation), so:

syms a b c d 
[a,b,c,d] = solve(a^2+b*c==-1, a*b+b*d==1, a*c+c*d==-1, d^2+b*c==0, [a,b,c,d])

Without using MATLAB, use the paper and pencil approach.