How do you find the derivative of $y = \frac{4}{cos x}$ $y = 4 / cosx$ ?

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Answer 1 · 2016-06-22T08:46:39

$4 sec x tan x$ $4 sec x tan x$

$( 4 / cosx)' = 4 (( cosx)^{-1} )'$

$= 4 (-1( cosx)^{-2} (-sin x))$

$= 4 (1/( cosx)^{2} (sin x))$

$= 4 sec x tan x$

How do you find the derivative of y = 4 / cosxy=4cosxy = 4 / cosx?