Question

can some1 help with the following question?

Answer 1

Find the values of k for which the quadratic form \[5x _{1}^{2}+x _{2}^{2}+kx _{3}^{2}+4x _{1}x _{2}-2x _{1}x _{3}-2x _{2}x _{3}\]is positive definite.

Answer 2

@joemath314159 @LagrangeSon678 @mahmit2012 @satellite73

Answer 3

that in the form x' * A * x. Then, positive definite is when all leading principal minors are greater than zero. Set k so that happens.

Answer 4

write that in the form... *

Answer 5

im still not sure how to start up the problem