Question

convert the given polar coordinates to rectangular coordinates.(10, pi/5)

i know
x=rcosQ
y=rsinQ

i guess i plug in 10 cos(pi/5)? right??

Answer 1

oh god why >.>

Answer 2

HAHA

Answer 3

Im sorry if i am completely blank

Answer 4

this stuff was the worst part of my junior year xD

Answer 5

HAHA, dang how old are you? i never took this in HighSchool. my highest was Algebra

Answer 6

I'm 17. and yes, to get x you plug in \[10\cos (\pi/5)\] and for y \[10\sin (\pi/5)\]

Answer 7

well i tried that x=10 cos pi/5 --> 9.99 ?
y=10 sin pi/5--> .0349

Answer 8

yup I think so

Answer 9

okay, i have a question tho now. i got this question wrong and the instructor circled my pi/5 and wrote radians.
isnt it in radians?

Answer 10

yes, should it be degress?

Answer 11

lol it doesnt say, but i dont know why she circledit lol. THANK YOU OH SO VERY MUCH!!!!! i really appreciate it. UGH i gotta do better on this test make up.

Answer 12

Have a goodnite!

Answer 13

i got a test make-up friday and a test tomorrow

Answer 14

Calc, is much easier imo

Answer 15

oh boy, :/ i would def. fail that. lol i hope so i have to get all the way to calc 2 i think.
Well im logging off. thank you very much. Have a goodnite

Answer 16

if you ever need calc help, I'm an @ away. night

Answer 17

haha

Answer 18

***
well i tried that x=10 cos pi/5 --> 9.99 ?
y=10 sin pi/5--> .0349
***

right idea, but you had your calculator in "degree mode" rather than "radian mode" so you are getting the wrong answer

the safest way to do this is change pi/5 radians to degrees
you do this by multiplying by 180/pi
\[ \frac{\cancel{\pi}}{5} \text{ rads} \cdot \frac{180}{\cancel{\pi}}= \frac{180}{5}= 36º \]

now, with your calculator in "DEGREE MODE" do
10*cos(36)= 8.08
10*sin(36)= 5.88

your rectangular coordinates are (8.08, 5.88)

Answer 19

oh right, because theta always gives a polar answer, thanks :D