Question

1- cosa/ 1+ cosa is formula for

Answer 1

Heya!!!

1 - Cos a = 2 Sin² ( a / 2 )

And

1 + Cos a = 2 Cos ² ( a / 2 )


1 - Cos a / 1 + Cos a = Tan² ( a / 2 )


Have a nice day ahead.

Answer 2

Answer: $tan^{2}( \frac{a}{2})$

Step-by-step explanation:

• Solving $\frac{1-cos a}{1+cos a}$

                  (1 - cos a)= $2 sin^{2} (\frac{a}{2} )$

                  (1 + cos a)= $2 cos^{2} (\frac{a}{2} )$

• Now, $\frac{1-cos a}{1+cos a}=\frac{2sin^{2}\frac{a}{2} }{2cos^{2}\frac{a}{2} }$

                            =$tan^{2}( \frac{a}{2})$

• Hence, $\frac{1-cos a}{1+cos a}$ is the formulae for $tan^{2}( \frac{a}{2})$.

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