problem with Solve-function

>> solve('k=0.3*(y1*y2)* (k^psi + y2) ^ ((1-psi)/psi)','k') Warning: Explicit solution could not be found. > In solve at 83

ans =

[ empty sym ]

>> psi

psi =

   -0.6667

>> y2

y2 =

    0.6667

>> y1

y1 =

215.1657

>> solve('k=0.3*( 215.1657*0.6667)* (k^(-0.6667) + 0.6667) ^ ( (1-(-0.6667)) /(-0.6667) )','k')

ans =

100.23898600309546274125023175854

So why can't the solve function find this solution???

Answer 1

[Walter Roberson]

The argument you sent to solve() was a quoted string. When you pass a quoted string, the value of any MATLAB variables is not used.

solve(subs(sym('k=0.3*(y1*y2)* (k^psi + y2) ^ ((1-psi)/psi)')),'k')

or

syms k
solve(0.3*(y1*y2)* (k^psi + y2) ^ ((1-psi)/psi) - k, k)