Question

MV Calculus: 2H-6A
Question: http://ocw.mit.edu/courses/mathematics/18-02sc-multivariable-calculus-fall-2010/2.-partial-derivatives/part-a-functions-of-two-variables-tangent-approximation-and-optimization/problem-set-4/MIT18_02SC_SupProb2.pdf
Answer: http://ocw.mit.edu/courses/mathematics/18-02sc-multivariable-calculus-fall-2010/2.-partial-derivatives/part-a-functions-of-two-variables-tangent-approximation-and-optimization/problem-set-4/MIT18_02SC_SupProbSol2.pdf

From page 10 on, I can not follow the solution to this problem anymore.
In the first part, we took partial derivatives continu

Answer 1

and found the critical points. What does the triangle in the part of the solution on page 10 represent. What is going on here haha.

Answer 2

R is just the domain of x, y, z ( in triangle shape )

Answer 3

I don't quite understand yet what the reason is for expressing the domain in triangle shape im afraid

Answer 4

Since x ≥ 0, y ≥ 0 and z ≥ 0
The region is limited in the first quadrant and the line x + y ≤ 4

Answer 5

hmm that makes sense
thanks, im just rather unfamiliar with this technique

Answer 6

It's kind of wordy, the expression just means domain in the first quadrant :)

Answer 7

yeah got it, thanks :)