3 Unit Exam Questions! Please Help! (2 Viewers)

juicystar07 · Mar 25, 2011

Hi!
I really need help with these two questions! Thankyou!

SpiralFlex · Mar 25, 2011

1. $LHS = \frac{\sin ^2\theta }{\cos ^2\theta }- \frac{\sin ^2\theta\cos ^2\theta }{\cos ^2\theta }$

$= \frac{\sin^2\theta (1-\cos^2\theta )}{\cos^2\theta }$

$= \frac{\sin^2\theta}{\cos^2\theta} * sin^2\theta$

$= tan^2\theta * \sin^2 \theta$

$= RHS$

2. Draw a general triangle. (ie. Adjacent side is 2 and Hypotenuse is 3)

By Pythagoras, opposite side is $\sqrt{5}$

Now, $\tan^2(90-\theta) = \cot^2 (\theta)$

Our $\cot\theta = \frac{2}{\sqrt{5}}$ (From the triangle we drew.)

Hence, $\cot^2\theta = \frac{4}{5}$

$\therefore \tan^2(90-\theta) = \frac{4}{5}$
Check answers to see if working is correct.

ohexploitable · Mar 25, 2011

juicy

juicystar07 · Mar 26, 2011

thankyou so much! i swear, @spiralflex, you are a genius! why cannot I not be like you!

and yes, @ohexploitable

jason2kool · Mar 28, 2011

the answer is definitely in the question.

3 Unit Exam Questions! Please Help! (2 Viewers)

juicystar07

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SpiralFlex

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ohexploitable

hey

juicystar07

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jason2kool

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