Sunday

April 20, 2014

April 20, 2014

Posted by **BT** on Monday, March 1, 2010 at 8:39pm.

(2, 3pi/4)

(-4, 7pi/6)

(2/3, -2pi/3)

Given the rectangular coordinates of a point, how do I find the polar coordinates?

(4, 0)

(3, 4)

(2, -2)

- trig -
**Reiny**, Monday, March 1, 2010 at 9:04pmIn (2,3pi/4) r = 2 and the rotation angle is 3pi/4 radians or 135º

make a sketch, draw you angle first, then go out 2 units on that ray.

drop a line to the x-axis, you now have a right-angled triangle in the II quadrant with an outside angle of 135º, and a hypotenuse of 2.

the inside angle is 45º, so it is isosceles.

Use Pythagoras to find each of the sides to be 1

But you are in quadrant II, so the point is (-1,1)

Do the others the same way

For the second type,

plot the point, then make a diagram showing the right-angled triangle.

You will have the x and the y.

Use Pythagoras to find r,

then tan ß = y/x will let you find the angle.

**Related Questions**

Math - plot the point given in polar coordinates and find the corresponding ...

Math - A point in polar coordinates is given, Find the corresponding rectangular...

trig - convert the point with polar coordinates (2,7pi/6) into rectangular ...

Math - The rectangular coordinates of a point are given. Find two sets of polar ...

Physics - If the rectangular coordinates of a point are given by (4,y), and its ...

pre calc.Math - Please help me any one of these please! Thank You to any one r=...

TRIGONOMETRY - 3. The rectangular coordinates of a point are given. Find the ...

Math - The rectangular coordinates of a point are given. Find two sets of polar ...

Math - The rectangular coordinates of a point are given. Find two sets of polar ...

Trigonometry - 1)Find the polar coordinates of the point whose rectangular ...