What are the components of the vector between the origin and the polar coordinate (8, (5pi)/6)?

1 Answer
Jul 24, 2016

((-4sqrt3),(4))

Explanation:

To convert from color(blue)"polar to cartesian coordinates"

That is (r,theta)to(x,y)

color(orange)"Reminder"

color(red)(|bar(ul(color(white)(a/a)color(black)(x=rcostheta , y=rsintheta)color(white)(a/a)|)))

Here r = 8 and theta=(5pi)/6
color(blue)"----------------------------------------"
rArrx=8cos((5pi)/6)

color(orange)"Reminder"

color(red)(|bar(ul(color(white)(a/a)color(black)(cos((5pi)/6)=-cos(pi-(5pi)/6)=-cos(pi/6))color(white)(a/a)|)))

rArrx=-8cos(pi/6)=-8xxsqrt3/2=-4sqrt3
color(blue)"------------------------------------------------------------------"

and y = 8sin((5pi)/6)

color(orange)"Reminder"

color(red)(|bar(ul(color(white)(a/a)color(black)(sin((5pi)/6)=sin(pi-(5pi)/6)=sin(pi/6))color(white)(a/a)|)))

rArry=8sin(pi/6)=8xx1/2=4
color(blue)"----------------------------------------------"

Thus the components of the vector are ((-4sqrt3),(4))