Math, asked by anurakshitha28, 9 months ago

prove that 1 + cos theta divided by sin theta minus sin theta divided by 1 + cos theta is equal to 2 cot​

Answers

Answered by jasmine2004Kaur
34

Answer:

Hope it helps..

plz mark me as brainliest

Attachments:
Answered by muscardinus
8

LHS = RHS

Step-by-step explanation:

In this expression, we need to prove that,

\dfrac{1+\cos\theta}{\sin\theta}-\dfrac{\sin\theta}{1+\cos\theta}=2\cot\theta

Taking LHS,

\dfrac{1+\cos\theta}{\sin\theta}-\dfrac{\sin\theta}{1+\cos\theta}\\\\=\dfrac{(1+\cos\theta)^2-\sin^2\theta}{\sin\theta(1+\cos\theta)}

Using (a+b)^2=a^2+b^2=2ab

=\dfrac{(1+\cos\theta)^2-\sin^2\theta}{\sin\theta(1+\cos\theta)}\\\\=\dfrac{1+\cos^2\theta+2\cos\theta-\sin^2\theta}{\sin\theta(1+\cos\theta)}

Since, \sin^2\theta=1-\cos^2\theta

=\dfrac{1+\cos^2\theta+2\cos\theta-(1-\cos^2\theta)}{\sin\theta(1+\cos\theta)}\\\\=\dfrac{2\cos^2\theta+2\cos\theta}{\sin\theta(1+\cos\theta)}\\\\=\dfrac{2\cos\theta(\cos\theta+1)}{\sin\theta(1+\cos\theta)}\\\\=\dfrac{2\cos\theta}{\sin\theta}

Since, \dfrac{\cos\theta}{\sin\theta}=\cot\theta

=\dfrac{2\cos\theta}{\sin\theta}\\\\=\cot\theta\\\\=RHS

Hence, LHS = RHS

Learn more,

Trigonometry

https://brainly.in/question/15914611

Similar questions