4/7 × 3/4
(4 and 4 are cancelled )
7×3
the answer is 21
has critical points where the partial derivatives simultaneously vanish:
So we have three critical points to consider,
,
, and
.
The function has Hessian
At the critical points, we have
which means there is a minimum at (0, 0) of
;
which means
is a saddle point; and
which means
is also a saddle point.
Gerardo can run 1 mile in 11 minutes. Jeremy can run 1 mile in 8 minutes + 10 minutes lag time due to the fact that he began so far behind.
Mile 1: Jeremy 18 minutes, Gerardo: 11 minutes
Mile 2: Jeremy 26 minutes, Gerardo: 22 minutes
Mile 3: Jeremy 34 minutes, Gerardo: 33 minutes
Mile 4: Jeremy 42 minutes, Gerardo: 44 minutes