Respuesta :
Answer:
Here is the proof of the trigonometric identity
[tex]\frac{\csc x \cos x}{\tan x + \cot x} = \cos^2 x[/tex]
Given:
[tex]\frac{\csc x \cos x}{\tan x + \cot x}[/tex]
To prove:
[tex]\frac{\csc x \cos x}{\tan x + \cot x} = \cos^2x[/tex]
Step 1: Rewrite all trigonometric functions in terms of sine and cosine.
[tex]\frac{\csc x \cos x}{\tan x + \cot x} \\ = \frac{\frac{1}{\sin x} \cos x}{\frac{\sin x}{\cos x} + \frac{\cos x}{\sin x}} \\ = \frac{\cos x}{\sin x \cdot \frac{\sin x}{\cos x} + \cos x \cdot \frac{\cos x}{\sin x}} \\ \\ = \frac{\cos x}{\frac{\sin^2 x + \cos^2 x}{\sin x \cos x}} \\ \\ = \frac{\cos x}{\frac{1}{\sin x \cos x}} \\ \\ = \cos x \cdot \sin x \cos x \\ \\ = \cos^2 x [/tex]
Step 2:Simplify the expression.
[tex]\cos^2 x = \cos^2 x[/tex]
Conclusion:Therefore,
[tex]\frac{\csc x \cos x}{\tan x + \cot x} = \cos^2 x.[/tex]
Hence Proved:
Answer:
[tex]\dfrac{ \csc x \cos x}{\tan x + \cot x}=\cos^2 x[/tex][tex]\textsf{Rewrite $\csc x=\dfrac{1}{\sin x}}, \tan x=\dfrac{\sin x}{\cos x}$, and $\cot x=\dfrac{\cos x}{\sin x}$:}[/tex]
[tex]\boxed{\dfrac{ \dfrac{1}{\sin x} \cdot \cos x}{\dfrac{\sin x}{\cos x} + \dfrac{\cos x}{\sin x}}}=\cos^2 x[/tex]
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{\sin^2 x }{\sin x + \cos x}+\dfrac{\cos^2 x }{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{\sin^2 x + \cos^2 x}{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{1}{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\boxed{\dfrac{\cos x}{\sin x} \cdot \sin x \cos x}=\cos^2 x[/tex]
[tex]\cos^2 x=\cos^2 x[/tex]
Step-by-step explanation:
Given trigonometric identity:
[tex]\dfrac{ \csc x \cos x}{\tan x + \cot x}=\cos^2 x[/tex]
[tex]\textsf{Use the identities\;\;$\csc x=\dfrac{1}{\sin x}$\;,\;$\tan x = \dfrac{\sin x}{\cos x}$\;\;and\;\;$\cot x=\dfrac{\cos x}{\sin x}$}:[/tex]
[tex]\textsf{Rewrite $\csc x=\dfrac{1}{\sin x}}, \tan x=\dfrac{\sin x}{\cos x}$, and $\cot x=\dfrac{\cos x}{\sin x}$:}[/tex]
[tex]\boxed{\dfrac{ \dfrac{1}{\sin x} \cdot \cos x}{\dfrac{\sin x}{\cos x} + \dfrac{\cos x}{\sin x}}}=\cos^2 x[/tex]
Simplify the numerator and make the fractions in the denominator like fractions:
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{\sin^2 x }{\sin x + \cos x}+\dfrac{\cos^2 x }{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\textsf{Apply\;the\;fraction\;rule\;\;$\dfrac{a}{b}+\dfrac{c}{b}=\dfrac{a+c}{b}$\;to\;the\;denominator}:[/tex]
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{\sin^2 x + \cos^2 x}{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\textsf{Use\;the\;identity\;\;$\sin^2x+\cos^2x=1$}:[/tex]
[tex]\boxed{\dfrac{\dfrac{\cos x}{\sin x}}{\dfrac{1}{\sin x + \cos x}}}=\cos^2 x[/tex]
[tex]\textsf{Apply\;the\;fraction\;rule\;\;$\dfrac{a}{\frac{b}{c}}=a \cdot \dfrac{c}{b}$}:[/tex]
[tex]\boxed{\dfrac{\cos x}{\sin x} \cdot \sin x \cos x}=\cos^2 x[/tex]
Cancel the common factor sin x, and apply the exponent rule aa = a²:
[tex]\cos^2 x=\cos^2 x[/tex]