SOLUTION: value of {{{sin(cot^-1 (x))}}}

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Question 872079: value of sin%28cot%5E-1+%28x%29%29
Answer by Edwin McCravy(20081) About Me  (Show Source):
You can put this solution on YOUR website!
sin(cot-1(x))

The way to interpret that problem is:

"Find the sine of the angle whose cotangent is x."

Let that angle be q.

We know that cotangent%22%22=%22%22%28adjacent%29%2F%28opposite%29

We also know that x can be written as x%2F1

So we draw a right triangle containing the angle q
with the side that is adjacent to q having length x
and the side that is opposite to angle q be 1.
Like this:

  

We have drawn a right triangle containing an angle whose
cotangent is x%2F1 which is x.

Now we calculate the hypotenuse by the Pythagorean theorem,
because we'll need that to find the sine.

hypotenuse2 = adjacent2+opposite2

hypotenuse2 = x2+12

hypotenuse = √x²+1

 

Now, we remember that the way to interpret the problem

sin(cot-1(x))

is:

"Find the sine of the angle whose cotangent is x."

And we let that angle be q.

So since sine%22%22=%22%22%28opposite%29%2F%28hypotenuse%29 

then,

sin(cot-1(x)) = sin(q) = 1%2Fsqrt%28x%5E2%2B1%29.

Edwin