Uploaded by vividmaths on 14.05.2012

Transcript:

Hi guys I am going to share with you reveal to you one of the biggest, most powerful,

most sineificant statements I could ever offer you in term of how to do bearing in fact how

to do trigonometry and all of math. This is particularly appropriate and suitable for

when you can have a problem like as follow. Now the drawing of the diagram, explain the

diagram taking those words and showing them as a diagram is the key thing so here is the

statement. A problem well drawn is a problem half solve so if you can draw takes those

words and turn them into wonderful picture you are half way there and the rest of it

is just smooth sailing you can just cruise through the solution so let us take a closer

look at this diagram and how it came about from this word so let us go through this words

again. A ship sails on a bearing of 200 degrees so you will always start from a port that

is quarter start somewhere and it start as a bearing so try the way you do across from

where you start. The first thing you do is find out where the bearing, the bearing is

says 200 degrees so you start zero flip all the way around for 200 hundred degrees that

is past 180 and now it is less than 270 it is going to be here somewhere. you can draw

rough if you want so you draw a line that is the first step now looking at the words

again. Now this is from O is in the question from O there we are there is a line 200 degrees

bearing if P is 18 nautical miles further west, further west than O, this O this west

that will use west yeah. so that is 18 nautical mile so let us put that in, out west so that

is 80, 80 nautical mile at that way. Ok so we got that way it is going at the way. What

other information do we have? Ahófind how far the ship is sail? Another one, is how

far this is? So let us put an X that is our missing pronumeral. So what do we have? We

have bearing 200 degrees let us write that in, we have 80 nautical miles west of O and

we have the missing pronumeral along here the distance that we are looking for X all

the way to the ship, so that is what we were after. Now we got the diagram drawn and displayed

we can now we can start to reduce had actually do this so we go to the step no. 2.

Step no. 2 we are actually looking at the diagram and calculating the angle that we

need because you probably noticed we have a right angle triangle here right? So we want

to find probably this angle in here so that can tell what this line here is, because we

have this line here, we got the 80 nautical miles yeah. we are looking for X here we need

that angle in there so that angle is going to be the angle Q O P, so angle--
that we are after, once we got
it looks like it is going to be adjacent over hypotenuse looks like probably going to be

a cos, but for now
degrees-- that is in total, all we need to do is take away the bearing all the way around

to here which is 200 degreesótake away 200 that is rather easy 270 ñ 200 is 70 degrees.

so we can safely put that angle in there so let us do that 70 degrees also . Ok now we

have that angle we can work out the trig rusher as I said earlier then determine what exactly

that length along here is. So let us do that now, so it looks like it is going to be --- over

here see how the 80 is next to the seventy? It is going up like that is next and it is

going to be ADJ and down here with this long length here is definitely a hypotenuse is

in it? The long length is not attach to the right angle. Ok now let us actually work with

this triangle now so we can actually work out on that link so it is going to be a cos

rusher because it is adjacent to the hypotenuse so write that down so we have --cos that angle

there which 70 degrees = adjacent which is 80 let us put that in-- / now it is going

to be all over the missing X right there the hypotenuse is in it? so let us put that X

there , ok this is our equation. Cos 70 =80/or an X, we are looking for X so I am going to

multiply both sides by X, times by X and times by X, multiplying both by X we are going to

be left on this side with a X cos 70 degrees = 80.now let us make X the subject let us

bring cos70 underneath and let us divide both sides by cos70 that will yield, X= that is

going to be all over cos 70, and on the top we have 80 of course , there is the 80 comes

there is the cos70 comes there, let me just draw a little arrow here, there, that is there.

Ok on the calculator 80 / cos70 gives you, the length of here the missing pronumeral

right there the X = on the calculator 233.9 newton nautical miles

Take a minute to check out our website at http://www.vividmaths.com. You will find additional

resources, cheat sheets, transcripts and other math videos that are not available on Youtube.

Lastly, donít forget to subscribe to get access to all the ready answer for all your

math questions plus other special offers.

most sineificant statements I could ever offer you in term of how to do bearing in fact how

to do trigonometry and all of math. This is particularly appropriate and suitable for

when you can have a problem like as follow. Now the drawing of the diagram, explain the

diagram taking those words and showing them as a diagram is the key thing so here is the

statement. A problem well drawn is a problem half solve so if you can draw takes those

words and turn them into wonderful picture you are half way there and the rest of it

is just smooth sailing you can just cruise through the solution so let us take a closer

look at this diagram and how it came about from this word so let us go through this words

again. A ship sails on a bearing of 200 degrees so you will always start from a port that

is quarter start somewhere and it start as a bearing so try the way you do across from

where you start. The first thing you do is find out where the bearing, the bearing is

says 200 degrees so you start zero flip all the way around for 200 hundred degrees that

is past 180 and now it is less than 270 it is going to be here somewhere. you can draw

rough if you want so you draw a line that is the first step now looking at the words

again. Now this is from O is in the question from O there we are there is a line 200 degrees

bearing if P is 18 nautical miles further west, further west than O, this O this west

that will use west yeah. so that is 18 nautical mile so let us put that in, out west so that

is 80, 80 nautical mile at that way. Ok so we got that way it is going at the way. What

other information do we have? Ahófind how far the ship is sail? Another one, is how

far this is? So let us put an X that is our missing pronumeral. So what do we have? We

have bearing 200 degrees let us write that in, we have 80 nautical miles west of O and

we have the missing pronumeral along here the distance that we are looking for X all

the way to the ship, so that is what we were after. Now we got the diagram drawn and displayed

we can now we can start to reduce had actually do this so we go to the step no. 2.

Step no. 2 we are actually looking at the diagram and calculating the angle that we

need because you probably noticed we have a right angle triangle here right? So we want

to find probably this angle in here so that can tell what this line here is, because we

have this line here, we got the 80 nautical miles yeah. we are looking for X here we need

that angle in there so that angle is going to be the angle Q O P, so angle--

a cos, but for now

to here which is 200 degreesótake away 200 that is rather easy 270 ñ 200 is 70 degrees.

so we can safely put that angle in there so let us do that 70 degrees also . Ok now we

have that angle we can work out the trig rusher as I said earlier then determine what exactly

that length along here is. So let us do that now, so it looks like it is going to be --- over

here see how the 80 is next to the seventy? It is going up like that is next and it is

going to be ADJ and down here with this long length here is definitely a hypotenuse is

in it? The long length is not attach to the right angle. Ok now let us actually work with

this triangle now so we can actually work out on that link so it is going to be a cos

rusher because it is adjacent to the hypotenuse so write that down so we have --cos that angle

there which 70 degrees = adjacent which is 80 let us put that in-- / now it is going

to be all over the missing X right there the hypotenuse is in it? so let us put that X

there , ok this is our equation. Cos 70 =80/or an X, we are looking for X so I am going to

multiply both sides by X, times by X and times by X, multiplying both by X we are going to

be left on this side with a X cos 70 degrees = 80.now let us make X the subject let us

bring cos70 underneath and let us divide both sides by cos70 that will yield, X= that is

going to be all over cos 70, and on the top we have 80 of course , there is the 80 comes

there is the cos70 comes there, let me just draw a little arrow here, there, that is there.

Ok on the calculator 80 / cos70 gives you, the length of here the missing pronumeral

right there the X = on the calculator 233.9 newton nautical miles

Take a minute to check out our website at http://www.vividmaths.com. You will find additional

resources, cheat sheets, transcripts and other math videos that are not available on Youtube.

Lastly, donít forget to subscribe to get access to all the ready answer for all your

math questions plus other special offers.