How do you find the exact value of $cos ({tan}^{- 1} 2)$ $cos(tan^-1 2)$ ?

Question

How do you find the exact value of $cos ({tan}^{- 1} 2)$ $cos(tan^-1 2)$ ?

1 Answer

Impact of this question

14181 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-21T09:57:51

A tangent of $\frac{2}{1}$ $2/1$ is opposite $2$ $2$ , adjacent $1$ $1$ so hypotenuse $\sqrt{2^{2} + 1^{2}} = \sqrt{5},$ $sqrt{2^2+1^2}=sqrt{5},$ so cosine of $\pm \frac{1}{\sqrt{5}}$ $pm 1/sqrt{5}$ or if we mean the principal value

$cos (Arc tan (2)) = \frac{1}{\sqrt{5}}$ $cos( text{Arc}text{tan}(2)) =1/sqrt{5}$

Explanation:

Stop using the ${tan}^{- 1} (x)$ $tan^-1(x)$ notation -- $arctan (x)$ $arctan(x)$ is better, and is the official standard.

Science

Math

Humanities

... and beyond

How do you find the exact value of $cos ({tan}^{- 1} 2)$ $cos(tan^-1 2)$ ?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you find the exact value of cos(tan−12)cos(tan^-1 2)?

1 Answer

Explanation:

Related questions

Impact of this question

How do you find the exact value of $cos ({tan}^{- 1} 2)$ $cos(tan^-1 2)$ ?