#ATTENDANCE QUIZ for Lecture 7 of Math251(Dr. Z.)
#EMAIL  RIGHT AFTER YOU WATCHED THE VIDEO
#BUT NO LATER THAN  Sept. 28, 2020, 8:00PM (Rutgers time)
#THIS .txt FILE (EDITED WITH YOUR ANSWERS)
#TO:
#DrZcalc3@gmail.com
#Subject: aq7
#with an ATTACHMENT CALLED:
#aq7FirstLast.txt
#(e.g. aq7DoronZeilberger.txt)




#LIST ALL THE ATTENDANCE QUESTIONS FOLLOWED BY THEIR ANSWERS

#Question 1

Find two parallel derivatives of f(x,y) = x^0 + 9x^0*y^3

Answer:
f(x,y) = 1 + 9y^3

f(x,y) =  9y^3
f(x,y) = (27/3)y^3

#Question 2

Fix f_x(z(x,y)) and f_y(z(x,y))

Answer:
y^2 * z^9 + x^2 * y^3(27) * z^3 

f_x(z(x,y)) =  2x
f_y(z(x,y)) =  2y +3y^2

#Question 3

Find f_y(1,1) 

Answer:

2+3 = 5
Answer:5

#Question 4

Is f_y(1,1) also zero?

Could you have predicted it?


Answer:

No and yes

#Question 5

Find the equation of the targent plane to the surface using: z = 1 + y^9 at the point (1,1,2)

Answer:

9y^8

At y: 2304

2304(x-2)