7th - MATH 120 RECITATION QUESTIONS (WEEK 7) 1. Using...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MATH 120 RECITATION QUESTIONS (WEEK 7) 1. Using different directions to approach the origin, show that the following limits do not exist. a) b) lim (x,y)(0,0) xy x2 + y 2 xy 2 (x,y)(0,0) x2 + y 4 lim 2. Using the formal definition of the limit prove a) b) lim lim (2x - 3y) = 1 (x,y)(2,1) x2 y 2 =0 (x,y)(0,0) x2 + y 2 3. Find f1 (3, -2) and f2 (3, -2) if x a) f (x, y) = arcsin( ) y x b) f (x, y) = y cos(t2 ) dt x y+z 4. Find fx , fy , fzy and fzyz given f (x, y, z) = 5. Define f (x, y) = x2 xy if (x, y) = (0, 0) and f (0, 0) = 0.Use the definition of partial deriva+ y2 tives to find f1 (0, 0) and f2 (0, 0). Note:In problem 1(a) above we showed that if f is discont. at the origin, so it should not be differentiable there.But the partial f1 and f2 exist, explain. 1 ...
View Full Document

Ask a homework question - tutors are online