Find the stationary porits of:

$f(x)=x_1^2+2x_2^2+4x_3^2+5x_1{x}_2$

Subject $to{x}_1+x_2^2+3x_2{x}_3=5$

$x_1^2+5x_1{x}_2+3x_3^2=9$

and determine their nature