Question

Which set of rectangular coordinates describes the same location as the polar coordinates:

(6√2, 3pi/4)

Please explain. Thank you!

Answer 1

x=rcos(theta) , y=rsin(theta) . That should help...

Answer 2

r=6√2 and theta=3pi/4 right?

Answer 3

Correct :)

Answer 4

Find x, and y by plugging in for r and (theta)

Answer 5

6√2cos(3pi/4)=8.48

Answer 6

6√2sin(3pi/4)=0.35

Answer 7

What is cos(3pi/4), it's definitely not a positive number!

Answer 8

0.999154554

Answer 9

You don't have your calculator in radians.

Answer 10

\[\cos \frac{ 3\pi }{ 4 }=\frac{ -\sqrt{2} }{2 }\]

Answer 11

http://www.wolframalpha.com/input/?i=cos%283pi%2F4%29