How do you convert the polar coordinate (-2,5pi/4) into cartesian coordinates?

2 Answers
Oct 21, 2015

(2,5π4) [polar] =(2,2) [Cartesian]

Explanation:

In Polar form:
(2,5π4)=(2,π4)
(draw a diagram if this isn't obvious)

For an angle of π4 the "opposite" and "adjacent" sides (i.e. x and y) are equal
and since x2+y2= the radius =2

x=y=2

Oct 21, 2015

The solution is (2;2). See explanation for details.

Explanation:

The given coordinates are not correct, because r cannot be negative (it is a distance between 2 points and it is either zero or a positive real number).

If the given point was (2;5π4) then corresponding Carthesian coordinates would be:

x=rcosφ=2cos(5π4)=2(cos(π4))

=2(22)=2

y=rsinφ=2sin(5π4)=2(sin(π4))

=2(22)=2

So the Carthesian coordinates are (2;2)