SOLUTION: how to find all points when r = 3sin(theta) and r = 3 cos (2 theta) intersect

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Question 958073: how to find all points when r = 3sin(theta) and r = 3 cos (2 theta) intersect
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
sin%28theta%29=cos%282%2Atheta%29
sin%28theta%29=1-2sin%5E2%28theta%29
Let u=sin%28theta%29,
u=1-2u%5E2
2u%5E2%2Bu-1=0
%28u%2B1%29%282u-1%29=0
Two solutions:
u%2B1=0
u=-1
sin%28theta%29=-1
theta=270
and
2u-1=0
2u=1
u=1%2F2
sin%28theta%29=1%2F2
theta=30 and theta=150