SOLUTION: Convert to polar: {{{ y = 4 }}} A.) {{{ r=4}}}/cosΘ B.) {{{ r=4}}}cosΘ C.) {{{ r=4}}}sinΘ D.) {{{ r=4}}}/sinΘ

Algebra ->  Trigonometry-basics -> SOLUTION: Convert to polar: {{{ y = 4 }}} A.) {{{ r=4}}}/cosΘ B.) {{{ r=4}}}cosΘ C.) {{{ r=4}}}sinΘ D.) {{{ r=4}}}/sinΘ      Log On


   

Question 1079670: Convert to polar: +y+=+4+
A.) +r=4/cosΘ
B.) +r=4cosΘ
C.) +r=4sinΘ
D.) +r=4/sinΘ
Found 2 solutions by MathLover1, Edwin McCravy:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

reminder:
x=+r%2Acos%28theta%29
y=+r%2Asin%28theta%29
so, if y=4, we will have
4=+r%2Asin%28theta%29
4%2Fsin%28theta%29=+r
and, your answer is: D.) +r=4/sinΘ

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
I like to explain why, when possible, not just spout formulas.

Here's why!

Draw this simple picture.

 

sin%28theta%29=opposite%2Fhypotenuse

sin%28theta%29=y%2Fr

+y+=+4+  <-- given

Substitute 4 for y

sin%28theta%29=4%2Fr

Solve for r

sin%28theta%29%2F1=4%2Fr

Cross multiply

r%2Asin%28theta%29=4

r=4%2Fsin%28theta%29

Edwin