which expression is equivalent to (cos x) (tan(-x))

Question

zepdrix · Answer

Hey!
$\Large\bf \color{#CC0033}{\text{Welcome to OpenStudy! :)}}$

`which expression`
Do you have some options for us to look at?

zepdrix · Answer

Recall that `tangent is an odd function`.
Therefore $\Large\rm \tan(-x)=-\tan x$

zepdrix · Answer

$$\Large\rm \cos x \tan(-x)=-\cos x \tan x$$

zepdrix · Answer

Then recall your tangent identity,$$ \Large\rm \tan x=\frac{\sin x}{\cos x}$$

zepdrix · Answer

You should be able to simplify things with that information.
Understand how to proceed?

anonymous · Answer

tan is sin/cos 

giving sin^2 / cos + cos 
now get common denoms 

sin2/cos + cos2/cos 

sin2 + cos2 = 1 

so you're left w/ 

1/cos = sec

zepdrix · Answer

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