SOLUTION: Find an equivalent equation in rectangular coordinates for the equation r=4sin(θ) Thanks

Algebra ->  Trigonometry-basics -> SOLUTION: Find an equivalent equation in rectangular coordinates for the equation r=4sin(θ) Thanks       Log On


   

Question 987500: Find an equivalent equation in rectangular coordinates for the equation r=4sin(θ)
Thanks
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
r+=+4sin%28theta%29

Always substitute for the trig functions first using 
sin%28theta%29=+y%2Fr, cos%28theta%29=x%2Fr, tan%28theta%29=y%2Fx.

r+=+4%28y%2Fr%29

Clear of fractions by multiplying through by r

r%5E2+=+4y

Finally replace r by sqrt%28x%5E2%2By%5E2%29 or in this case r%5E2 by x%5E2%2By%5E2 but always 
wait till the last step to substitute for r.

x%5E2%2By%5E2=4y

Edwin