To solve the problem you must know that to change from Cartesian to polar coordinates you must write:
x = rcos (θ)
Where "r" is the radius
Likewise y = rsin (θ)
Therefore, in the expression r = 3cos (θ) one can write r as:
r = x / cos (θ)
So:
x / cos (θ) = 3cos (θ)
x = 3cos ^ 2 (θ)
The same for y ...
y = rsin (θ)
y = 3cos (θ) sin (θ).
Finally the correct answer is option 2.
x = 3cos ^ 2 (θ) y = 3cos (θ) sin (θ).
It would be the first answer. Bubble. I don't know what you call it. But yeah, it's the first one.
Add 10 to both sides to cancel out the 10
divide 2 on both sides
X= 18
15.
0.20*x = 0.01*x + 38 => 0.19*x = 38 =>( 19/100 )*x = 38 => x = 3800/19 => x = 200.
(x -1)(x +4) = 0
x² +3x -4 = 0 . . . . . . probably the form you're looking for
