Show that secx + rt3 cosecx = 4

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In summary, the conversation discusses how to show that the equation secx + rt3 cosecx = 4 can be written in the form sinx + rt3cos x = 2sin2x. The conversation touches on using trig identities and multiplying by sinx and cosx, as well as the importance of understanding and memorizing these identities. There is also a brief discussion about the notation rt3, which is assumed to mean √3.
  • #1
matt_crouch
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1

Homework Statement



Show that secx + rt3 cosecx = 4 can be written in the form sinx + rt3cos x = 2sin2x

Homework Equations





The Attempt at a Solution



Didnt really know where to start with this one. trig identities maybe?
cheers
 
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  • #2
Hi matt_crouch! :smile:
matt_crouch said:
Show that secx + rt3 cosecx = 4 can be written in the form sinx + rt3cos x = 2sin2x

oh come on!

whenever you see sec or cosec, multiply everything by cos and/or sin :smile:
 
  • #3


Im probably missing a really obvious step. But i still don't know where to start.

If i write the equation as 1/cosx + 1/rt3sinx = 4 and i multiply by sinx and cosx to get

1 + 1/rt3 =4cosxsinx

and I am not sure but can the RHS be written as 2sin2x?
am i heading in the right direction cos I am still stuck as to how i can get 1+ 1/rt3 can be written as sinx + rt3cosx
 
  • #4


That's some pretty nasty algebra on the RHS. You are multiplying by sin(x)*cos(x). How did you get the 1's and why did sqrt(3) move into the denominator?
 
  • #5
matt_crouch said:
If i write the equation as 1/cosx + 1/rt3sinx = 4 and i multiply by sinx and cosx to get

1 + 1/rt3 =4cosxsinx

erm … sinx + cosx/rt3 =4cosxsinx :redface:

but how did that rt3 get on the bottom? :confused:
and I am not sure but can the RHS be written as 2sin2x?

Yes!

You must learn these trigonometric identities and be sure of them! :smile:
 
  • #6


ya i really have.. =]

basically i had no idea what i was doing. Confused the hell out of myself so tore the page out an started again.. =]
 
  • #7


Sorry for asking, but what is rt3?
 
  • #8
Дьявол said:
Sorry for asking, but what is rt3?

i assumed it was √3 … but does it matter?
 
  • #9


In this case, it doesn't. I wanted to know in case if I find rt3 again somewhere. Thanks tiny-tim.
 

1. What is the purpose of showing that secx + rt3 cosecx = 4?

The purpose of showing this equation is to prove a trigonometric identity and establish a relationship between the trigonometric functions of secant and cosecant.

2. How do you solve this equation?

To solve this equation, we need to use algebraic manipulation and trigonometric identities. We can start by multiplying both sides by secx to get secx + rt3 cosecx secx = 4secx. Then, using the identity secx cosecx = 1, we can simplify to get secx + rt3 = 4secx. From here, we can use the Pythagorean identity secx^2 = 1 + tanx^2 to rewrite the equation as (1 + tanx^2) + rt3 = 4(1 + tanx^2). Finally, we can solve for tanx and use its inverse function to find the value of x.

3. What is the significance of the value 4 in this equation?

The value 4 represents the right-hand side of the equation and is the result of simplifying the left-hand side using trigonometric identities. It is significant because it shows that secx + rt3 cosecx is equivalent to 4, further supporting the trigonometric identity being proven.

4. Can this equation be proven using other methods?

Yes, there are multiple ways to prove this trigonometric identity. Some other methods include using the double angle formula for sine and cosine, converting all trigonometric functions to only sine and cosine, and using the fact that secx = 1/cosx and cosecx = 1/sinx.

5. How is this equation applicable in real-world situations?

This equation may be applicable in real-world situations where trigonometric functions are used, such as in engineering, physics, and navigation. It can also be used to solve problems involving triangles and angles, as well as in the study of periodic functions.

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