SOLUTION: Convert the rectangular equation to polar form. (Use r and use theta for θ as necessary.) x2 + y2 = 18

Algebra ->  Trigonometry-basics -> SOLUTION: Convert the rectangular equation to polar form. (Use r and use theta for θ as necessary.) x2 + y2 = 18       Log On


   

Question 867565: Convert the rectangular equation to polar form. (Use r and use theta for θ as necessary.)
x2 + y2 = 18
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2%2By%5E2=18, which is really %28x-0%29%5E2%2B%28y-0%29%5E2=%28sqrt%2818%29%29%5E2 is in the form %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2 which is a circle with center (h,k) = (0,0) and radius r%5E2=18 ---> r+=+sqrt%2818%29


Now simplify r+=+sqrt%2818%29


r+=+sqrt%2818%29


r+=+sqrt%289%2A2%29


r+=+sqrt%289%29%2Asqrt%282%29


r+=+3%2Asqrt%282%29


So the answer, as simplified as possible, is r+=+3%2Asqrt%282%29. This is because this is simply a circle with radius 3%2Asqrt%282%29 and when you have something like r+=+2, you mean "a circle with center (0,0) with radius 2"