Volume = 13 x 10 x 11 = 1430 ft²
Answer: 1430 ft²
The answers are 7, 3, -1, -5
(In that order) :)
The diagram shows that FG = IJ are congruent segments due to the double tickmarks. These are the hypotenuses of the right triangles.
So that takes care of the "H" in "HL".
The L stands for "leg", so we need to have a congruent pair of corresponding legs.
Due to the orientation of the triangles, it's not clear how the corresponding legs match up, but if any of the following is true
- EF = IK
- EF = JK
- EG = IK
- EG = JK
then we'd have enough to use HL.
Critical points occur where the gradient is zero. This is guaranteed whenever
and either
or
.
The Hessian matrix for this function looks like
and has determinant
Maxima occur whenever the determinant is positive and
. Minima occur whenever both the determinant and
are positive. Saddle points occur whenever the determinant is negative.
At
, you have a saddle point since the determinant reduces to -324, so
is the saddle point.
At
, the determinant is
and
, so
is a local maximum.
No other critical points remain, so you're done.
