What is the distance between (2,5π6) and (4,7π4)?

1 Answer
Mar 26, 2017

d=25262.132

Explanation:

Polar coordinates: (r,θ)

Find location of (4,7π4):
Start at the x-axis and go 7π4=315, Since r=4, rotate 180: (4,7π4)=(4,3π4)

Convert both to rectangular coordinates (rcosθ,rsinθ)

(2,5π6)=(2sin(5π6),2cos(5π6))=(232,212)=(3,1)

(4,3π4)=(4cos(3π4),4sin(3π4))=(422,422)=(22,22)

Find the distance between the points d=(y2y1)2+(x2x1)2:

d=(221)2+(223)2
d=(221)(221)+(22+3)(22+3)
d=942+1146
d=204246
d=4(526)
d=25262.132