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System Message

[00:00:00] *** Please note: All sessions are recorded for quality control. ***

Ariel (Customer)

[00:00:00] I need help with solving a problem

Eric K (Tutor)

[00:00:07] Welcome to Tutor.com ! I'm Eric.

[00:00:19] How may I help you today?

Ariel (Customer)

[00:00:36] convert each polar equation
to a rectangular equation

[00:00:41] they only gave me r=10

[00:01:03] I dont know how to solve it
since I think I'm missing what
y is

Eric K (Tutor)

[00:01:23] I see! Let me give you a hint on this one.

[00:02:11] Using that formula on the right, how can you rewrite the r?

[00:02:46] Almost! Tell me it this is what you did:

[00:02:53] you took the square root of both sides right?

[00:03:24] The only thing is you can't simplify that anymore

Ariel (Customer)

[00:03:25] yes

Eric K (Tutor)

[00:04:19] Awesome! Now you have a formula for r

[00:04:49] You take it from here!

Ariel (Customer)

[00:05:24] but then what about finding
the 0

[00:05:38] dont i use tan0=y/x?

[00:05:44] I dont even know what those
value are

Eric K (Tutor)

[00:05:57] This one doesn't have an angle actually!

[00:06:03] Work it out and see what it comes out too

[00:06:21] it may look strangely familiar....

[00:06:36] so r is all you need for this one

[00:07:34] There you go! I want you to do one more step: square both sides

[00:08:45] Are you familiar with conic sections: circle, ellipses, etc.

[00:08:49] ?

Ariel (Customer)

[00:08:49] yes

Eric K (Tutor)

[00:08:56] What's that an equation of?

Ariel (Customer)

[00:09:22] a circle

Eric K (Tutor)

[00:09:32] Pretty neat huh?

Ariel (Customer)

[00:09:47] yes

Eric K (Tutor)

[00:09:49] let me show you something else too

[00:10:07] if you were to graph the equation r = 10

[00:10:21] there is no angle so the angle could be anything

Ariel (Customer)

[00:10:28] I see

[00:10:35] that makes sense

Eric K (Tutor)

[00:10:42] but r or the radius always has to be 10!

[00:10:48] Awesome!

[00:11:07] Is there anything else I could help you with or clear up?

Ariel (Customer)

[00:11:16] yeah

[00:11:25] I have a similar problem

Eric K (Tutor)

[00:11:38] Sure!

Ariel (Customer)

[00:12:00] am I suppose to mkae it y or x
=?

Eric K (Tutor)

[00:12:27] You mean in the end like this:

Ariel (Customer)

[00:13:16] no

Eric K (Tutor)

[00:13:54] Oh I see...let's take a look

[00:14:43] Let's try a slightly different approach

[00:14:49] how could you rewrite sec?

Ariel (Customer)

[00:15:48] sec=1/cosx

Eric K (Tutor)

[00:15:52] Yes!

[00:16:15] Then do you see what you can do?

Ariel (Customer)

[00:16:32] no

[00:16:48] we dont know the angle
measure

Eric K (Tutor)

[00:16:51] Hang on let's do one more step...

[00:16:57] multiply both sides by cos

Ariel (Customer)

[00:17:34] which makes x=6

Eric K (Tutor)

[00:17:38] There you go!

[00:18:42] The way you were doing it before would've have worked but one would simplify and the other would not. Is it okay if I show you really quickly?

Ariel (Customer)

[00:19:03] sure

Eric K (Tutor)

[00:20:00] so that one works out

[00:21:15] and the second one doesn't really simplify as well when you work it out

[00:21:59] So the other method works! Just takes a little longer!

Ariel (Customer)

[00:22:22] I see

Eric K (Tutor)

[00:22:26] and actually if you wanted too

[00:22:37] make the sin/cos into tan

[00:22:52] and then tan = y/x

[00:23:11] then divide both sides by y

[00:23:44] oh look! It does come out the same actually! A lot more work though.

Ariel (Customer)

[00:24:02] so there is more than one way
to do this problem

Eric K (Tutor)

[00:24:19] Yep! Usually there are a bunch of ways to do these problems

Ariel (Customer)

[00:24:31] The first way was the shortest
then?

Eric K (Tutor)

[00:24:34] as long as you get all into x's and y's you're good

[00:24:38] Yep!

[00:25:00] Is there anything I could clear up about what we did?

Ariel (Customer)

[00:25:05] no

Eric K (Tutor)

[00:25:23] Okay! It was good working with you!