IDNLearn.com provides a seamless experience for finding and sharing answers. Discover the information you need from our experienced professionals who provide accurate and reliable answers to all your questions.

1. Prove the following trig identity
tan(x/2)=sinx/1+cosx​


Sagot :

Step-by-step explanation:

[tex] \tan( \frac{x}{2} ) = \frac{ \sin(x) }{1 + \cos(x) } [/tex]

[tex] \tan( \frac{x}{2} ) = \frac{ \sqrt{1 - \cos(x) } }{ \sqrt{1 + \cos(x) } } [/tex]

So we have

[tex] \frac{ \sqrt{1 - \cos(x) } }{ \sqrt{1 + \cos(x) } } = \frac{ \sin(x) }{ \sqrt{1 + \cos(x) } } [/tex]

Next, we then rationalize the numerator so we get

[tex] \frac{ \sqrt{1 - \cos(x) } }{ \sqrt{1 + \cos(x) } } \frac{ \sqrt{1 + \cos(x) } }{1 + \cos(x) } = \frac{ \sin(x) }{ {1 + \cos(x) } } [/tex]

The denominator should be square root so to let you know .

So know we ahev

[tex] \frac{ \sqrt{1 - \cos {}^{2} (x) } }{1 + \cos(x) } = \frac{ \sin(x) }{1 + \cos(x) } [/tex]

[tex] \frac{ \sqrt{ \sin {}^{2} (x) } }{1 + \cos(x) } = \frac{ \sin(x) }{ {1 + \cos(x) } } [/tex]

[tex] \frac{ \sin(x) }{1 + \cos(x) } = \frac{ \sin(x) ) }{1 + \cos(x) } [/tex]