Trigonometric Functions..Tan and Cos

M

mathmarauder

Junior Member
Joined
Oct 25, 2008
Messages
68
Ok im having a real problem here.
I have a triangle
a is on the bottom = 3
b on the right side
c on the sloped side
and the degree of the angle on the bottom left (a beta symbol) is 73 degrees.
90 degrees in the bottom right.
find b,c, and the unknown angle (the alpha symbol). alpha = 17 degrees

but here is the solution..to which i am lost
it supplies the properties of right triangle formula c squared = a squared and b squared.
then it has two symbols i believe the alpha and beta symbols, they look similiar to the letters a and B. alpha and beta = 90 degrees.
solving for b
b over 3 = tan 73 degrees
b = 3 tan 73 degrees
b (swirly equal sign) roughly = 9.81
it said to multiply both side by 3 and then simplify.
My question is how did they get 9.81
im confused about multiplying by 3 and how that turned
b = 3 tan 73 degrees into
b roughly = 9.81
and if you know of a free online calculator that can do this would help also.
But i just need to be able to get 9.81 and i have no idea how
(round to nearest hundredth)
Thank you and hopefully i supplied enough info
 
wow if you are asking me whats the problem, i really must be lost :)
how did b = 3tan73 degrees
turn into
b roughly = 9.81
the two dont seem to go to together
9.81 to me came from no where
and since we are on the topic
i have no clue where you got "tan (73) = 3.2709..."
that from


Thank you very much for the link and help by the way
 
mathmarauder said:
Ok im having a real problem here.
I have a triangle
a is on the bottom = 3
b on the right side
c on the sloped side
and the degree of the angle on the bottom left (a beta symbol) is 73 degrees.
90 degrees in the bottom right.
find b,c, and the unknown angle (the alpha symbol). alpha = 17 degrees

but here is the solution..to which i am lost

it supplies the properties of right triangle formula c squared = a squared and b squared.
then it has two symbols i believe the alpha and beta symbols, they look similiar to the letters a and B. alpha and beta = 90 degrees.
solving for b
b over 3 = tan 73 degrees
b = 3 tan 73 degrees
b (swirly equal sign) roughly = 9.81
it said to multiply both side by 3 and then simplify.
My question is how did they get 9.81
im confused about multiplying by 3 and how that turned
b = 3 tan 73 degrees into
b roughly = 9.81
and if you know of a free online calculator that can do this would help also.
But i just need to be able to get 9.81 and i have no idea how
(round to nearest hundredth)
Thank you and hopefully i supplied enough info
Click to expand...

I'm guessing that you have some very basic problems here....

You are TOLD that one angle in your triangle has a measure of 90 degrees. So, that makes your triangle a rIght triangle. Now, the the side opposite the right angle in a right triangle is the hypotenuse (is that what you're calling the "slanted side"??) and the two sides which form the right angle are called the LEGS of the triangle.

When you say
it supplies the properties of right triangle formula c squared = a squared and b squared

I'm thinking that you are missing some VERY BASIC knowledge about right triangle relationships.

In any right triangle, if you square the lengths of the two legs, and add those two squares together, you will always get the square of the hypotenuse.

If, in a right triangle, "a" and " b" represent the lengths of the legs, and "c" represents the length of the hypotenuse, then

a^2 + b^2 = c^2

You say, though, c squared = a squared AND b squared.

I'm sorry...this indicates to me that you need MUCH more help than we can give you here.

Please see your teacher for help. You may also want to consider employing a tutor who can sit down face-to-face with you several hours a week until you get caught up with the basic knowledge you need.
 
yes the hypotenuse is the slanted side. a right triangle.
Thank you for the advice. Im pulling like 40 hours a week trying to learn this stuff.
I believe i know the basics.
i mentioned the c squared formula because it was just a side note inculded int he wrok shown on how to solve the problem,
thought it would be a helpful thing to include.

but i am confused mostly about tangent i guess.

b = 3tan 73 degrees. That makes sense
but then simplifying it, it turns into
b = 9.81
and that is what does not make sense.
if someone could tell me how they simplified that
to make it = 9.81
Oh and by the way, i wasnt told that an angle was 90 degrees. I was just explaining it that way.
It shows that little box on the bottom right corner of the triangle.

Thank you for the help
 
mathmarauder said:
... i have no clue where you got "tan (73) = 3.2709..."
Click to expand...


Denis uses a computer.

If you use one of the Windows operating systems, then you can, too.

Go to the Accessories subfolder, and click on Calculator.

On the menu bar of the calculator's application window, click View, and select Scientific.

Click View, again, and make sure that both Decimal and Degress are also selected.

Type 73.

Click on the [tan] button.

The display reads 3.27085 ...

This is the value of the tangent of a 73-degree angle.

Click on the multiplication button.

Type 3.

Hit enter.

The display reads 9.81255 ...

That is three times 3.27085 ...

It seems to me that you need to study basic right-triangle trigonometry to learn the meaning of the trigonometric functions (eg: sine, cosine, and tangent). Start at the Great God Google; you will be rewarded with many fine explanations (if you invest the time).

Cheers,

~ Mark :)

 
THANK YOU!!!! woohoo. And yes more and more and more studying is in order.
My question has been answered :)
 
mathmarauder said:
i have no clue where you got "tan (73) = 3.2709..." from
Thank you very much for the link and help by the way
Click to expand...
Ah c'mon, buddy...did you at least LOOK at the link?
It's there, in black and white: TAN 73 = 3.2709

That means that with a right triangle with angles 90, 73 and 17 and with a=1, then b=3.2709;
but since a=3, then b= 3 * 3.2709...kapish?

Seems you're asking "WHERE do these numbers come from?"; teacher didn't explain?
Well, if not, go here: http://id.mind.net/~zona/mmts/trigonome ... angle.html
 
mathmarauder said:
THANK YOU!!!! woohoo. And yes more and more and more studying is in order.
My question has been answered :)
Click to expand...
Whoops...didn't see this post...glad you're catching on...

And consider yourself lucky to be able to use calculators:
in my days, we had no choice but to use them damn tables,
plus do the multiplication by hand :cry:
 
Oh and what confused me about the link wich i did look at :p
this was in the tan column .3057 so I was like...hmm thats a great link but
it doesnt have the answer. :)
The link is useful thank you :)
 
You must log in or register to reply here.
Top