How do you evaluate $sec(tan^-1(2))$ ?

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Answer 1 · 2018-04-28T08:08:36

$=> sec ( tan^(-1) (2) ) = sqrt(5)$

Let $theta = tan^(-1) (2)$

$=> tan theta = 2$

We know $1 + tan^2 theta = sec^2 theta$

$=> 1 + 2^2 = sec^2 theta$

$=> sec^2 theta = 5$

$=> sec theta = sqrt(5)$

$=> sec ( tan^(-1) (2) ) = sqrt(5)$

How do you evaluate sec(tan^-1(2))sec(tan^-1(2))?