Math Is Fun Forum

Zeeshan 01

Member

Registered: 2016-07-22

Posts: 746

angles

in trigonometry why we dont work with angles such as we cannot divide any thing with angle wht is this angles???? ex (sinô)2 is equal to.sin square thita

---

Malik

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: angles

Hi;

What question are you asking?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Mathegocart

Member

Registered: 2012-04-29

Posts: 2,226

Re: angles

I am going to interpret that you are saying "why do we use radians instead of angles in trigonometry?"
Welll many trig functions have many characteristics(periods,allowed values, etc) that make radians particularily handy.
Look, which looks more convenient? Radians....or degrees?

The number pi, as strange as it seems, is at the heart of mathematics. The number 360 isn't. Clinging to 360 instead of pi will not allow you to see the beauty of trigonometry.
How we found the radian:
Let's just start with any old circle and wrap the radius of the circle around the circle.

See how it forms a angle? We'll call that a RADIAN.
Now, let’s take that radius and wrap it around the outside of the circle. See how it forms an angle? We’ll call that angle 1 radian.


nearly 180 degrees, 3 radians.
Now we have fit nearly 6 radians in

There's a little bit remaining.
We get
C = 2πr.
There are exactly 2pir radians in a circle!

Last edited by Mathegocart (2016-07-26 05:04:13)

---

The integral of hope is reality.
May bobbym have a wonderful time in the pearly gates of heaven.
He will be sorely missed.

Zeeshan 01

Member

Registered: 2016-07-22

Posts: 746

Re: angles

question is if there is sin 2thitha /2thitha why it not equal to sin only

---

Malik

zetafunc

Moderator

Registered: 2014-05-21

Posts: 2,432

Website

Re: angles

does not mean

It is a function of

.

Zeeshan 01

Member

Registered: 2016-07-22

Posts: 746

Re: angles

Function of thetha means please explain this misconception

---

Malik

Bob

Administrator

Registered: 2010-06-20

Posts: 10,143

Re: angles

hi Zeeshan 01

Think of a function as a box that takes in a number and outputs another number.

Here you can see what happens when the number 30 is the input.  Four different functions give four different outputs.

sin(30) is a single number.  sin(90) is also a number [ sin(90) = 1 ]

If you have one function divided by another you must work out the value of each function first before you do the division:

You cannot separate the function from its number by cancelling or you get the wrong result. 

Hope that helps,

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Zeeshan 01

Member

Registered: 2016-07-22

Posts: 746

Re: angles

Thx it clearing me!!,, slowly slowly

---

Malik