Question

Please Help!!

Find the rectangular coordinates of the point with the polar coordinates (1, 1/2 pi).

Answer 1

@phi

Answer 2

use x= r cos(A) and y = r sin(A)
(which if you know trig, you could have puzzled out by noticing you have a triangle and you need to find its base (x value) and height (y value)

Answer 3

I'm in pre-cal but I don't understand any of this

Answer 4

1=r cos(A)
1 1/2 pi=r sin(A)?

Answer 5

Let's start by getting the ideas straight.

when they write
(1, 1/2 pi)
they mean that pair to stand for (r, A)
where r is the distance from the origin, and A is the direction (the angle)

Unfortunately, the way they write it looks just like (x,y)
In fact, if you were not told the polar coordinates (1, 1/2 pi).
there would be no way to know you did NOT have (x,y) coordinates.

Answer 6

ok, so
x=1 cos(1 1/2pi)
y=1 sin(1 1/2pi)

Answer 7

yes, but what is 1 ½ pi ?
the angle is the second number in the pair (1, ½ pi)
A is pi/2

Answer 8

oh gosh, i kept reading that wrong sorry

Answer 9

When you have time, watch this (it will probably help a lot)
http://www.khanacademy.org/math/precalculus/parametric_equations/polar_coor/v/polar-coordinates-1

Answer 10

ok

Answer 11

so you should get
x=0
y=1

Answer 12

i kept getting
x=1
y=0

Answer 13

x= cos(pi/2)
y = sin(pi/2)
pi/2 is the same as 90º

Answer 14

Did you use a calculator? Are you in radian mode? btw, people memorize the sin, cos and tan of pi/2

Answer 15

ohh ok i'm not in radian mode

Answer 16

Thank you :)

Answer 17

yw