1.

Can someone please help me with this trigonometry problem!​

Answer»

2

Step-by-step explanation:

Given:

cosec A = 2

To find:

The value of

\dfrac{1}{ \tan A}  +  \dfrac{ \sin A}{1 +  \cos A}

Solution:

cosec A = 2

As, We KNOW

cosec 30° = 2

So, cosec A = cosec 30°

A = 30°

Now,

\frac{1}{ \tan A}  +  \frac{ \sin A}{1 +  \cos A} \\  \\ \frac{1}{ \tan30}   +   \frac{ \sin30}{1 +  \cos 30} \\  \\  \cot30 +  \frac{ \frac{1}{2} }{1 +  \frac{ \sqrt{3} }{2} }  \\  \\  \sqrt{3} +  \frac{ \frac{1}{2} }{ \frac{2 +  \sqrt{3} }{2} }  \\  \\  \sqrt{3}   +  \frac{1}{2}   \times  \frac{2}{2 +  \sqrt{3} }  \\  \\  \sqrt{3} +  \frac{1}{2 +  \sqrt{3} }  \\ \\ [\text{Rationalizing the denominator}] \\  \\  \sqrt{3} \:    + \frac{(2 -  \sqrt{3}) }{(2 +  \sqrt{3} )(2 -  \sqrt{3} )} \\  \\  \sqrt{3} +  \frac{2 -  \sqrt{3} }{(2){}^{2}  -  {( \sqrt{3} )}^{2} }   \\  \\  \sqrt{3}    + \frac{2 -  \sqrt{3} }{4 - 3}  \\  \\  \sqrt{3}   + 2 -  \sqrt{3}  \\  \\ 2

Hence, The required answer is 2.

Some IMPORTANT trigonometry RULES:

sinø . cosecø = 1

cosø . secø = 1

tanø . cotø = 1

sin²ø + cos²ø = 1

cosec²ø - cot² = 1

sec²ø - tan²ø = 1

Trigonometry Value

See in the ATTACHMENT.



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