Hi i was wondering if anyone can help me with this problem.. i was thinking of using Lagrangian's multipliers method to solve this., but i alsos get confused with transpose part i.e. (^t)

i need to find an expression in terms ofsfor the minumum value of(x^t)xsubject to the constraint(s^t)x = k

sis a fixed vector inR^n

kis a real constant

and i also need to justify this is a minimum

if anyone can help..that would be great thanks