62.3k views
16 votes
Determine two pairs of polar coordinates for the point (5, -5) with 0° ≤ θ < 360°

User Sergeyne
by
3.6k points

2 Answers

9 votes
X=5 Y=-5 is the answer I think?
User Gilles Heinesch
by
3.9k points
4 votes

Answer:

Explanation:

x=5

y=-5

Hence it lies in 4th quadrant.

x=r cos θ

5=r cos θ ...(1)

y=r sin θ

-5 =r sin θ ... (2)

square and add

(5)²+(-5)²=r²(sin ²θ +cos ²θ )

r²=25+25=50

r=±5√2

dividing

tan θ=-5/5=-1=-tan 45°=tan (180-45),tan(360-45)

θ=135°,315°

so polar coordinates are (5√2,315°) and (-5√2,135°)

User Goma
by
3.8k points