juriemagic

Good morning Melody,

Uhm I have a book here, with Maths 4 Africa..., it'slike a study guide, and it gives identities with examples...On one page it says GENERAL SOLUTIONS as head line, then 5 types

Type 1 says Sina=number

Type 2 says Sina=2Cosa

Type 3 says Sina=Cosb

Type 4 says Cosx=Cos(x+30)

and then type 5 is all about 2 or more terms...

it's okay, Melody, don't mean to waste your time with this...There is an example of what the author means, however does not make sense to me...

NOPE...LET'S SKIP THIS ONE......Thanks for replying though 

Perfect, I just love this...thank you Melody

PLEASE COME TO SOUTH AFRICA!!!

YOU MAKE THIS SOO VERY EASY TO UNDERSTAND...

If you did this using Calculus...would you get the derivative of the \(2Sin(4x)\)?..I tried that...but got stuck?

Melody, once again, ..Thank you. So it's all about rasionalizing the numerator. I could do it like this:?

\({{\sqrt2 \over2}(SinxCosx)} \over Sinx\)

\({{{\sqrt2 \over2}(SinxCosx)} \over Sinx}*{ \sqrt2 \over \sqrt2}\)

which really means:

\({{{\sqrt2* {\sqrt2} \over2}(SinxCosx)} \over \sqrt2Sinx}\)

which will then also produce the final correct answer?

By the way, the brackets were needed...I have forgotten to add them in the original sum...oopsie..sorry..

my my my ...goodness!!!..off course!

gosh, you know what Melody...I have looked at for example Sin 140, as Sin 140 DEG, and therefore could not understand how on earth 135 DEGREES could be the same as 45 DEGREES

but yes, I see my error. Getting the actual values of the different Sin values, equate to the same answer....ALL RIGHTIE!!!... 

Just a last thing...The different quads where the trig functions are either positive or negative, I fully understand, I use the phrase CAST, starting with quad 4...C=Cos, A=All, S=Sin and T=Tan...(obviously..)

Thank you Melody for going through the trouble of finding those urls, I have not watched them, since I understand all of this, I just made a stupid error for mistaking the value for an angle...

I'm sending a BIG BUNCH of flowers!!

Good morning Melody,

You are such a great help to me, thank you so so much..

I have gone through the answers very SLOWLY, taking in and seeing the cartesian plane, and I have suddenly realized why we start of with 

\(x=360-\) or \(x=360+\) or \(x=180 +/-\)

because it depends which quads you work with....Finally this has become clear...I am only left with the last parts which say \(+/- 360n/180n\)

If only that can be explained please. I have a hunge that it may have to do with limits?..or restrictions?

Hewllo sweet Melody!!,

Thank you for replying....Melody, may I ask why we always use the "+360n" thingy????

Also, the answers in the memorandum indicates:x=153,43 deg +k.180

                                                                       OR x=153,43 deg +k.360

                                                                       OR x=333,43 deg +k.360 for (CosX + 2SinX)=0

and                                                                       x=9,74 deg +k.180 

                                                                      OR x=180,26 deg +k.180. for  (3sin 2x-1)=0

Also, you have added values..(more answers)....This is something I truly do not grasp...please will you explain for dummies? 

Hello asinus,

I do appreciate your response and explanation. I'm not sure how I saw this, because I input the measurments in an app, and got an error message. AAAHHH, wait, something just occured to me now while typing here...OBVIOUSLY the long side cannot be greater or equal than the two shorter sides combined, because if it was at least equal, we would have two straight parrallel lines....NOT exceeding, in this case, 200. COMMON SENSE ....

Gosh, forgive my stupidity please, wasting your time on something like this. I do appreciate your time. 

Hi Cphill,

so in other words my aproach was correct, the answer in this case is 16?

Hi Melody,

looking at those you gave, the y value will be y+2

and f(n) will be f(n+5).....right?