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1/cos x + tan x [identity] cos x / 1 - sin x​

1/cos x + tan x [identity] cos x / 1 - sin x​-example-1
User Mrusful
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1 Answer

7 votes

The simplified expression is
(sin\theta+cos\theta)/(1- sin^2 \theta) .

To simplify the expression
(1)/(cos \theta) + tan \theta = (cos \theta)/(1 - sin\theta) , let's follow a similar approach as before:

Combine the fractions in the numerator:


(1)/(cos \theta) + tan \theta = (sin\theta +cos \theta)/(cos\theta)

Invert and multiply by the reciprocal of the denominator:


(sin \theta + cos \theta)/(cos \theta) * (1 - sin\theta)/(cos\theta)
= ((sin\theta+cos\theta)(1- sin\theta))/(cos^2\theta)

​Expand the numerator:

=
(sin\theta+cos\theta- sin\theta cos\theta + cos\theta sin\theta)/(cos^2\theta)

Combine like terms:

=
(sin\theta+cos\theta)/(cos^2 \theta)

​Now, if you want to express this in terms of trigonometric identities, you can use the Pythagorean identity
sin^2 \theta +cos^2\theta = 1 to replace
cos^2\thetain the denominator:

=
(sin\theta+cos\theta)/(1- sin^2 \theta)

Therefore, the simplified expression is
(sin\theta+cos\theta)/(1- sin^2 \theta) .

User Umeboshi
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8.9k points