What is the simplest form of the expression below?

[tex]\[
\frac{\cot (\theta) \cos (\theta)}{\sin (\theta)} \cdot \tan (\theta) \div \frac{\sin (\theta)}{\cos (\theta) \tan (\theta)}
\][/tex]

A. [tex]\(\sec \theta\)[/tex]

B. [tex]\(\cot \theta\)[/tex]

C. [tex]\(\csc \theta\)[/tex]

D. [tex]\(\tan \theta\)[/tex]



Answer :

Let's simplify the given expression step by step. The expression to simplify is:

[tex]\[ \frac{\cot (\theta) \cos (\theta)}{\sin (\theta)} \cdot \tan (\theta) \div \frac{\sin (\theta)}{\cos (\theta) \tan (\theta)} \][/tex]

First, we rewrite [tex]\(\div\)[/tex] as the multiplication by the reciprocal:

[tex]\[ \frac{\cot (\theta) \cos (\theta)}{\sin (\theta)} \cdot \tan (\theta) \cdot \frac{\cos (\theta) \tan (\theta)}{\sin (\theta)} \][/tex]

Now, let's simplify each component of the expression:

1. [tex]\(\cot(\theta)\)[/tex] is defined as [tex]\(\frac{\cos(\theta)}{\sin(\theta)}\)[/tex].

So,

[tex]\[ \frac{\cot (\theta) \cos (\theta)}{\sin (\theta)} = \frac{\left( \frac{\cos (\theta)}{\sin (\theta)} \right) \cos (\theta)}{\sin (\theta)} = \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \][/tex]

2. The expression now becomes:

[tex]\[ \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \cdot \tan (\theta) \cdot \frac{\cos (\theta) \tan (\theta)}{\sin (\theta)} \][/tex]

Recall that [tex]\(\tan(\theta)\)[/tex] is defined as [tex]\(\frac{\sin(\theta)}{\cos(\theta)}\)[/tex]. Substitute [tex]\(\tan(\theta)\)[/tex] into the expression:

[tex]\[ \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \cdot \frac{\sin(\theta)}{\cos(\theta)} \cdot \frac{\cos (\theta) \frac{\sin(\theta)}{\cos(\theta)}}{\sin (\theta)} \][/tex]

We can simplify this step-by-step:

3. Simplify [tex]\(\frac{\sin(\theta)}{\cos(\theta)}\)[/tex]:

[tex]\[ \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \cdot \frac{\sin (\theta)}{\cos (\theta)} \][/tex]

4. Notice that [tex]\(\frac{\cos (\theta) \frac{\sin(\theta)}{\cos (\theta)}}{\sin (\theta)} = \frac{\sin(\theta)}{\sin (\theta)}\)[/tex] simplifies to 1:

5. Now the expression reduces to:

[tex]\[ \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \cdot \frac{\sin (\theta)}{\cos (\theta)} \cdot 1 \][/tex]

6. Let's combine the simplified components:

[tex]\[ \frac{\cos^2 (\theta)}{\sin^2 (\theta)} \cdot \frac{\sin (\theta)}{\cos (\theta)} = \frac{\cos (\theta)}{\sin^2 (\theta)} \cdot \sin (\theta) = \frac{\cos (\theta)\sin (\theta)}{\sin^2 (\theta)} \][/tex]

7. Now, simplify [tex]\(\frac{\cos (\theta)}{\sin (\theta)}\)[/tex]:

[tex]\[ \frac{\cos (\theta)}{\sin (\theta)} = \cot (\theta) \][/tex]

Thus, the simplest form of the given expression simplifies to:

[tex]\[ \cot (\theta) \][/tex]

So, the correct answer is:

[tex]\(\boxed{\cot (\theta)}\)[/tex]