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Eind the limitう。itana.ス

Answer»

so we can useL'Hospital's rule.

d/dx(numerator ) = sec ^2 x -1 = tan ^2 x d/dx(denominator = (x^2 sec ^2 x+ 2x tan x)

so tan ^2 x/((x^2 sec ^2 x+ 2x tan x)

= (tan x/x) (tan x/( x sec^2 x+ 2 tan x)

tan x/x -> 1 and

tan x/( x sec ^2 x + 2 tan x)

is reciprocal of

( x sec ^2 x + 2 tan x)/ tan x = ( x (1/cos^2x tan x) + 2 = x/(cos x sin x) + 2 = (x/sin x)(1/cos x) + 2 = 1 .1 + 2 = 3

so tan x/( x sec ^2 x + 2 tan x) = 1/3

so tan ^2 x/((x^2 sec ^2 x+ 2x tan x) or given expression = 1/3



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