Identify the curve by transforming the given polar equation to rectangular coordinates.
letter (d)
you only need to use below : \(x = r \cos \theta\) \(y = r \sin \theta \)
and notice that \(x^2 + y^2 = r^2\)
for #a : \(r = 2\) square both sides and replace r^2 by x^2+y^2, you're done.
still kinda unsure how to go about this problem :/
wait I'm sorry, i only need help with letter (d) !
oh you're doing letter d.. okay lol :)
hehe yes! thats the one :)
cross multiply
\[r = \dfrac{6}{3 \cos \theta + 2 \sin \theta}\] \[r(3 \cos \theta + 2 \sin \theta) =6\]
mk...\[r(3\cos \theta+2\sin \theta)=3\]
oops 6*
distribute \(r\)
let me do that real quick...!
okie
it looks a little weird :S ... let me write it
\[r3\cos \theta+r2\sin \theta=6\]
^?
a*b = b*a so, r*3 = 3*r
\[r = \dfrac{6}{3 \cos \theta + 2 \sin \theta}\] \[r(3 \cos \theta + 2 \sin \theta) =6\] \[ 3~r\cos \theta + 2~r \sin \theta =6\]
thats all? :) @rational
replace rcos and rsin by x and y
\(r\) and \(\theta \) are polar variables, so you're not done until u have them in ur equation
\[r = \dfrac{6}{3 \cos \theta + 2 \sin \theta}\] \[r(3 \cos \theta + 2 \sin \theta) =6\] \[ 3~r\cos \theta + 2~r \sin \theta =6\] \[ 3x+ 2y=6\]
Now you're done. so basically the given polar curve is just a straight line !
you were so helpful! thank you :D
np :)
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