# Thread: How'd they get cos out here?

1. ## How'd they get cos out here?

Hi folks,

Firstly this is the page I'm looking at to try and learn some trig,

SparkNotes: SAT Subject Test: Math Level 1: Trigonometric Identities

The question goes as follows

$\displaystyle (\cos\theta \times \tan\theta) / (\sin\theta -\cos\theta^2)$

In their working, they re write this as follows

$\displaystyle \frac{\cos\theta \times \tan\theta}{\sin\theta} - \cos\theta^2$

My question is - How did they get the $\displaystyle \cos\theta^2$ out from under the fraction? Shouldn't it be under there instead of out seperately?

Why isn't it

$\displaystyle \frac{\cos\theta \times \tan\theta}{\sin\theta - \cos\theta^2}$

Thanks folks.

2. Originally Posted by Peleus
Hi folks,

Firstly this is the page I'm looking at to try and learn some trig,

SparkNotes: SAT Subject Test: Math Level 1: Trigonometric Identities

The question goes as follows

$\displaystyle (\cos\theta \times \tan\theta) / (\sin\theta -\cos\theta^2)$

In their working, they re write this as follows

$\displaystyle \frac{\cos\theta \times \tan\theta}{\sin\theta} - \cos\theta^2$ Mr F says: This is wrong.

My question is - How did they get the $\displaystyle \cos\theta^2$ out from under the fraction? Shouldn't it be under there instead of out seperately?

Why isn't it

$\displaystyle \frac{\cos\theta \times \tan\theta}{\sin\theta - \cos\theta^2}$ Mr F says: This is right.

Thanks folks.
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