Expert: Paul Klarreich - 11/8/2010

Question
1. Find arc length of the curve: x=sqrt of 2t :
y= t^5/5-1/3t^3  1< and equal to t< and equal to 2

2. the Cartestian coordinates of a point are (3,-1) find the polar coordinates of this point?

Can you please help me with these two problems i am totally lost and i have a quiz soon. :(  

Answer
Questioner:   Tina
Country:  United States
Category:  Calculus
Private:  No
 
Subject:  second semester calculus problems
Question:  
1. Find arc length of the curve: x=sqrt(2t) :

y= t^5/5-1/3t^3  1 <= t <= 2

2. the Cartestian coordinates of a point are (3,-1) find the polar coordinates of this point?

Can you please help me with these two problems i am totally lost and i have a quiz soon. :(


1. Did you mean
    t^5      1
y = ----- - -----
     5      3t^3

or

    t^5     1
y = ----- - --- t^3
     5      3

without knowing this, I can't proceed.

2. Use  r = sqrt(x^2 + y^2)

and use  theta = arctan(y/x)

r = sqrt(10) and

theta = arctan(-1/3), which you can compute, and get something in quadrant IV.