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Question: How do you find the value of \(\operatorname{cosec} \,\pi \)?...

How do you find the value of cosecπ\operatorname{cosec} \,\pi ?

Explanation

Solution

In this question we need to find the value of cosecπ\operatorname{cosec} \,\pi . This question is related to finding the value of trigonometric functions to a corresponding degree. To find the value of, we need to know the definition of cosec\operatorname{cosec} \,trigonometric function. It is a periodic function with its period equal to2π2\pi .

Complete step by step solution:
Let us try to find the value ofcosecπ\operatorname{cosec} \,\pi . To find the value ofcosecπ\operatorname{cosec} \,\pi , we need to know the definition of cosec\operatorname{cosec} \,function.

Trigonometric functions are those functions which provide a relationship between angles of the right angle triangle and its sides. cosec\operatorname{cosec} \,(Cosecant) is also a one of those trigonometric functions.

In terms of the side of the right angle triangle, it is defined by Hypotenuse upon the perpendicular.

Let θ\theta be the angle of a right angle triangle then

cosecθ=HypotenusePerpendicular\operatorname{cosec} \,\theta \, = \,\dfrac{{Hypotenuse}}{{Perpendicular}}

As we know thatsinθ=perpendicularHypotenuse\sin \theta \, = \,\dfrac{{perpendicular}}{{Hypotenuse}}.

So, we can see that there is a relation between sinθ\sin \theta and cosecθ\operatorname{cosec} \,\theta trigonometric function. Both of them are reciprocal of each other which means that
cosecθ=1sinθ\operatorname{cosec} \,\theta \, = \,\dfrac{1}{{\sin \theta }}

We use this above relation to find the value of cosecπ\operatorname{cosec} \,\pi . To find the value sinπ\sin \pi and use the relation between sinθ\sin \theta and cosecθ\operatorname{cosec} \,\theta trigonometric function.

As we know that sin2θ=2sinθcosθ\sin 2\theta \, = \,2\sin \theta \cos \theta

Here2θ=πθ=π22\theta \, = \,\pi \Rightarrow \,\,\theta = \dfrac{\pi }{2}. Putting values of θ\theta in the formula we got
sinπ=2sinπ2cosπ2\sin \pi = 2\sin \dfrac{\pi }{2}\cos \dfrac{\pi }{2}

As we know the value of sinπ2=1\sin \dfrac{\pi }{2} = 1 andcosπ2=0\cos \dfrac{\pi }{2} = 0. We get the value ofsinπ=0\sin \pi \, = \,0.

From relation cosecθ=1sinθ\operatorname{cosec} \,\theta \, = \,\dfrac{1}{{\sin \theta }} we have
cosecπ=1sinπ\operatorname{cosec} \,\pi \, = \,\dfrac{1}{{\sin \pi }}

As we know the value ofsinπ=0\sin \pi \, = \,0. Also we have that dividing any number by 0 is undefined. So the value of

cosecπ=10==undefined\operatorname{cosec} \,\pi \, = \,\dfrac{1}{0} = \infty = undefined

Hence cosecπ\operatorname{cosec} \,\pi is undefined atπ\pi .

Note: In the question which asked to find the value of trigonometric values for some degree value. We must have to know the definition of the trigonometric function and its identities or relation with trigonometric functions. Trigonometric functions have applications in finding the large distances.