Reflection #10

This week wasn't that bad. Because we had a four day week, it went by pretty quick, almost having like two weekends...so this week we learned more about trigonometry...I'm going to discuss how to do trigonometrical inverses.

Trig inverses are used to solve for an angle.

You can't divide by a trig function, such as

sinO/sin = 2/sin

An inverse finds 2 angles, but there are exceptions:

sin^-1 (1)

sin^-1 (-1)

csc^-1 (1)

csc^-1 (-1)

cos^-1 (1)

cos^-1 (-1)

sec^-1 (1)

sec^-1 (-1)

Steps to find the inverse:

1. Use trig chart to find reference angles; if not on chart or unit circle, use calculator.

2. Determine the quadrants of your two angles.

3. Find the 2 angles

To move:

I to IV - make O negative

I to III - add 180 degrees

I to II - make O negative and add 180 degrees

II to IV - add 180 degrees

The only thing I'm really gonna have trouble with is remembering the chart, and I'm gonna have to study hard for this test on Tuesday. If someone could show me some word problems involving Jupiter's radius and diameter and stuff, that would be appreciated. Thanks.

I forgot how to do the great or less than thing.
some one explain pleaseeeee.

ok i been lost ever since we started chapter 7 the only thing i kinda understand is what we went over yesterd 7-6 trig inverse

the only thing im a little confused about that is the number is going to be neg. or pos.

?

How do you do the problems on the homework with the negatives in front of the degrees? Like on page 279, #1c. Find the reference angle sin(-37degrees).

homework?!

does anybody know what the homework is for tonight?

Reflection #9

Okay, one thing I know how to do: convert

From degrees to radians: multiply by pi/180
ex. 12o degrees times pi/180
120 pi/180
=pi/40

From radians to degrees: multiply by 180/pi
ex. 4 pi/3 times 180/pi
pi cancels out
4/3 times 180
720/3
=240 degrees

One thing I don't understand: word problems
??????? I have no idea...well, if some one could give an example problem then show how to work it, that'd be great.

Reflection 9.

Sooooo, this week we started trig. It really wasn't as bad as I thought it would be..yet. It's pretty much just memorizing the formulas and knowing when to use them. The thing I understood the best was converting degrees into radians and vice versa. To convert degrees to radians you multiply the degrees by Pi/180. Your final answer will have Pi in it. To convert radians to degrees multiply by 180/Pi. Pi will cancel out and you will be left with just the number.

Example: Degrees---->Radians

225 x Pi/180= 225/180Pi= 5/4Pi


Example: Radians---->Degrees

3/4Pi x 180/Pi= 135 Degrees

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I don't understand when you have to convert a decimal to degrees? or something like that. There's an example in our notes I just don't understand how to do that part.

Reflection #9!

So this week was quite laid back, of course our intro to trig doesn't seem TOO difficult yet but i know that sooner or later it's definitely going to come back and bite me in the butt!

For starters, i understood 7.2 the best but changing radians to degrees and vice versa seem like the easiest to explain:

In ALL word problems, when given degrees, you MUST change it into radians.
ALSO in ANY problem that calls for degrees, if you do not put the degree symbol, it is automatically understood to be in radians and will be marked WRONG on a test, BE CAREFUL!

Now, onto converting:

When given radians:
radians TIMES 180/pi.

When given degrees:
degrees TIMES pi/180.

EXAMPLE OF RADIANS:
2pi/8
2pi/8 TIMES 180/pi
2 TIMES 180/8
360/8
45 degrees.

EXAMPLE OF DEGREES:
45 degrees
45 TIMES pi/180
45/180pi
1/4pi
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This week there really wasn't anything that i did not understand,
except the coterminal angles? i'm not exactly sure where they fit in our notes and why...
anyone help? THANKS! :)

Reflextion 9

Well i'm glad exam week is finally over, and i thought i have done pretty well for the first nine weeks. I'm also glad of learning so much, never thought that would be possiable. This week was pretty is I thought, even though i wasnt there mentally on thursday and friday. We began doing trinomoetry stuff. O bot triangles, how i love them. hahaha, i wish. I also found out we get to do a bridge project and it sounds pretty fun. Hope i get that A again. Anyways we learn about an angle. They are measured in degrees, minutes, seconds.
To find the minutes multiply what is behind decimal by 60. To find seconds multiply what is behind deciaml of minutes by 60 than divide 3600 to get deciaml. And you must always use an exact answer, and never plug pi into the calculater. If the answer is not in degrees it will be wrong!!!!!!!!! And i understood a sector of a circle pretty well to. Trig is easy all i got to do is remember the formulas. Unfortunatly i forgot to bring my book home again so i cant do my hw, so i'm doubling up for tomorrow, anyone feelin a study group, ill have chips and dip

Reflection #9

Angles with the degrees, minutes, and seconds

Examples of converting degrees, minutes, and seconds to just degrees.

15 degrees 24 minutes, and 15 seconds

15 +24 over 60 for 1 hour + 15 over 3600 to get the decimal.

15 + 24/60 + 15/3600 = 15.404 degrees


And to find coterminal angles add or subtract 360 degrees or 2 pi.

Example: 225 degrees x pi over 180

225+pi/180 = 225/180pi = simplifies to 5pi/4

I SOMETIMES GET CONFUSED ON WHAT WE LEARNED IN CLASS ON FRIDAY IF I DONT LOOK BACK IN MY NOTES..:/

Reflection

well... due to the powerpoints, exams, and psat we didn't learn too much. What we did learn was converting degrees to radians and radians to degrees. degrees and radians are used to measure angles. To convert from radians to degrees you multiply radians by 180/pi and to convert from degrees to radians you multiply your degrees by pi/180.

Reflection #9

Okay so this week was super easy and relaxed!!! We did our powerpoints and that took up most of our time in class. We had our exam on monday and it was pretty easy. If you did all of your study guides, you shouldn't have had a problem. But i'm not going to lie, I didn't make what i wanted to make, but i did okay. And on Thursday and friday, we started on chapter 7. It is pretty simple if you do your homework and stuff.

____________________________________________________________
EXAMPLE: (convert to radians)

30 degrees
30 X pi/180
30/180 pi
1/6 pi

EXAMPLE: (convert to degrees)

pi/6
pi/6 X 180/pi
180/6
30 degrees

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We also learned how to do the word problems. They are so easy. Once i memorize the symbols and what they mean, I think that will be the simplest thing. But if you want to do an example problem for me, I would greatly appreciate it. THANKS :)

reflection 9

Soooooo, this week was pretty much power pointastic, except for chad...you noob! And we had the big game on Friday so i really didnt feel like doing anything this week, but i did remember how to change degrees, minutes and seconds to simply degrees.

10 degrees 25 minutes, and 15 seconds
10 +25 over 60 (for 1 hour in minutes) + 15 over 3600 (for 1 hour in seconds) to get the decimal.
10 + 25/60 + 15/3600 = 10.421 degrees

The word problems in trig confuse me, but finding central angles and me dont get along to well!!!

reflection 9

This week we didn't really learn much because of exams and everything. I don't think i did very good on my exam:x ha, i thought i knew how to do some stuff but i don't know. Hopefully my powerpoint will help out my grade, and those take home tests we got last week. I did understand the conversions that we learned the other day..

convert to radians
EXAMPLE:

30 degrees

30x pi/180

30/180 pi

1/6 pi

Reflection 9

This week we took our beast exam on monday, but im pumped because I actually got a B for the nine weeks. The next two to three days we finished doing power points. Then we learned some trigonometry stuff. I did get how to do the Angles with the degrees, minutes, and seconds stuff.

Examples of converting degrees, minutes, and seconds to just degrees.

15 degrees 24 minutes, and 15 seconds

15 +24 over 60 for 1 hour + 15 over 3600 to get the decimal.

15 + 24/60 + 15/3600 = 15.404 degrees


And to find coterminal angles add or subtract 360 degrees or 2 pi.

Example: 225 degrees x pi over 180

225+pi/180 = 225/180pi = simplifies to 5pi/4

On the other hand I did not know how to do the stuff friday and I do not know how to do numbers 7 and 11 on the homework.

Reflection #9

Alright this week we didn’t learn too much because of exams and getting ready for the big football game. But one thing that I understood this week was converting the radians to degrees and degrees to radians.
Here’s the steps:
know the formulas.
Radian=degrees x pi/180
Degrees=radian x pi/180

Here’s an example:
4 pi/ 16
4 pi/ 16 x 180/pi
4 x 180/ 16
720/ 16
45 degrees

Here’s an example
44 degrees
44 x pi/180
11/45 pi

***What I didn’t understand was how to find the measure of central angles.

I think that circles are the easiest thing in math, so far. Standard form is really simple.
(x-h)^2+(y-k)^2=r^2.
If it is not in standard form, you have to complete the square to get it in standard form.
The center of the circle is (h,k) and the radius is (r).
EX:(x-8)^2+(y+2)^2=36center (8,-2)radius = 6.

To find the intersection of a line and a circle:1) Solve the linear equation for y.2)
Substitute in circle equation.3)
Solve for x.4)
Plug x value in to get y value.
**If your x value is imaginary, then there is no point of intersection**

To graph the cirlce in your calculator:
Go to the Y= button, plug the equation in positive and then negative (if there is a gap, close it when you draw it on the paper)

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the word problems for trig are confusing me.

reflection 9

This week was very rough and boring especially with the whole rivalry thing goin on. it was kinda getn on my nerves but any way...

this week we learned about Radians and Degrees. Basically if you memorize your formula you'll be ight so.

Radian=degree x pi/180
Degree= radian x pi/180

covert to radian, 90 degrees

90 dg. x pi/180
90/180 pi
1/2pi= radian

and do the same thing to find degree...its very easy

REFLECTION #9

Alright so this week I finally got to get my powerpoint presentation over with. I'm so glad I don't have to worry about that any more but now I'm worried about building a bridge. Soooo that should be fun. hah. Well anyway, this week wasn't all that bad. Monday thru Wednesday we didn't really do much because of exams and whatnot. And we listened to everyone's presentations. Then on Thursday, when I saw "Trigonometry" written on the board my eyes like popped out of my head, because I know that's probably going to be hard stuff for me to grasp. ha. But it wasn't too bad, I'm still a tad confused but I'll get it eventually. Well hopefully I get it for that quiz tomorrow. So on Thursday we learned how to convert radians to degrees and how to convert degrees to radians. We also learned how to find coterminal angles. Then on Friday we learned three formulas (I don't exactly know what they're called) to solve problems.

Okay so what I thought was the easiest thing we learned this week was converting radians to degrees and converting degrees to radians. So I will try and explain that as best as I can.

Here are a few examples:

Example 1. Convert to radians: 30 degrees
30 x pi/180 (multiply 30 by pi over 180)
30 pi/180
1/6 pi (reduced fraction) or it can be written as pi/6 because 1 is the numerator

Example 2. Convert to degrees: 3 pi/4
3 pi/4 x 180/pi (multiply 3 pi/4 by 180/pi)
3 x 180/4 (*pi's cancel out so now you just multiply numbers)
540/4 = 135 degrees


**Alright now for what I did not completely understand this week. Well there's a lot of things really, but basically just little things. Like for instance, whenever you're asked to convert 95 degrees 10 minutes to radians, I don't know how to do that because I get confused. Also I get stumped whenever I see degrees with decimals in them like 119.2 degrees and you would have to convert it and whatnot. Sooooo if anyone would mind wasting their time to explain this more to me that would be appreciated :)

Reflection #9

This week wasn't that bad at all. All we did was basically take the exam and then learn about radians and degrees. Chapter 7: 7-1 and 7-2 were pretty easy; all you need to do is memorize your formulas and then just plug in. The week went by slow I guess, but at least next week we have Thursday off.

To find radians, you multiply the degrees by pi/180

radians = degrees x pi/180

To find degrees, you multiply radians by 180/pi.

degrees = radians x 180/pi

Example:

225 degrees, convert to radians

225 x pi/180 = 225 pi / 180 = 5/4 pi

Convert pi/6 to degrees.

pi/6 x 180/pi = 30 degrees

The only thing I'm still not sure about is the minutes and seconds stuff. But overall it was a pretty easy week.

reflection 9

well, this week was long and boring and painful, but thank god its over. nothing really happened this week, so theres nothin to ramble about. :/ so ill just get to the math.

one thing that i did understand this week was converting stuff.

convert to radians: 120º
120 X π/180=120/180 π
=12/18 π
=2/3 π

but one thing i dont understand is the whole thing with minutes and seconds thing