The function is
.
Compare it with standard form of quadratic function
.
Since
, then the graph of parabola open upward.
So the function has minimum value.
\Find the vertex of above quadratic function
.
coordinate of vertex is axis of symmetry
.
.
.
The minimum value is
.
.
Replace
with
.
.

Minimum point is
=
\ \
The minimum value of the function is
.
\