Simplifying Trig Expressions and cofunctions

In summary, the problem involves simplifying the expression sec^2x X cotx / cscx using the Pythagorean identities and basic trig function identities. To solve, the first step is to rewrite sec^2x as 1 + tan^2x and cotx as 1/tanx. Then, set up the expression as a complex fraction and simplify using the identities for secx, cscx, and cotx in terms of sinx and cosx. The final solution should not involve cotx being written as cosx/sinx.
  • #1
Mr. Mathmatics
10
0

Homework Statement


Sec^2x X cotx
---------------------
csc xAlso, if anyone wants to explain cofunction identities and how to use them, to be that would be very much appreciated.

Homework Equations


The Pythagorean identities as well as the basic identities of trig functions.

Any knowledge of cofunctions.

The Attempt at a Solution


I made sec^2x into 1 + tan^2x with one of the identities and broke down tan^2x into tanx X tanx.

I also assumed cot could not be broken down into anything but 1/ tanx, which is 1/ (sin/cos). But nothing canceled so I ended up back at the starting line.
 
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  • #2
so what are the identities for sec^2x, cotx, and cscx?

how would you set it up if you were to write it in original form (in terms of sin and cos).

question, are we just simplifying? you didn't state it in "1" so I'm just assuming.

if we're simplifying, my first step would be to set it up into a complex fraction, then simplifying the CF. i actually had 2 steps of a CF just so that i didn't get confused.
 
Last edited:
  • #3
The identities are the things like sec^2x equals 1+Tan^2x, etc. the basic ones.

As for the original form, that's what I'm trying to figure out. I think I have to put the problem in terms of Sin and Cos to simplify it. I'm hoping that's the answer at least.
 
  • #4
alright, so we're on the same page. instead of using 1+tan^2x, use sin and cos.

set up a complex fraction then simplify it (hint, don't put cotx in terms of cosx/sinx just yet)
 
  • #5
[tex]\sec{x} = \frac{1}{\cos{x}}[/tex]

[tex]\csc{x} = \frac{1}{\sin{x}}[/tex]

[tex]\cot{x} = \frac{\cos{x}}{\sin{x}}[/tex]

Remember that^^
 

Related to Simplifying Trig Expressions and cofunctions

1. What are cofunctions in trigonometry?

Cofunctions are pairs of trigonometric functions that have complementary angles. This means that the sine of one angle is equal to the cosine of the other angle, and vice versa. For example, the sine of 30 degrees is equal to the cosine of 60 degrees.

2. How do I simplify a trigonometric expression?

To simplify a trigonometric expression, you can use various trigonometric identities and properties. Some common techniques include factoring, using reciprocal identities, and using the Pythagorean identities. It is also important to remember to use the order of operations when simplifying an expression.

3. What is the sum of the cofunctions?

The sum of two cofunctions is always equal to 1. This is because their angles are complements of each other, meaning they add up to 90 degrees (or π/2 radians). For example, the sine of an angle plus the cosine of the same angle will always equal 1.

4. Can I use a calculator to simplify trigonometric expressions?

While a calculator can be helpful in verifying your answers, it is important to understand the steps and concepts behind simplifying trigonometric expressions. Relying solely on a calculator can lead to errors and a lack of understanding.

5. How can I check my work when simplifying trigonometric expressions?

One way to check your work is to use the identities and properties mentioned earlier and apply them to your simplified expression. Another way is to plug in specific values for the variables and compare the results to the original expression. If they are equal, then your simplification is correct.

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