Please help with some problems in trigonometry

[bloodborne]

Hello! I would be very happy if someone could help me with these exercises.

(for questions 1-3)
Let alpha be an acute angle. Suppose that cos alpha = 3/4. Compute:

1)
[MATH] \begin{equation} 3 cos(2\alpha) + 2 \end{equation} [/MATH]2)
[MATH] \begin{equation} \\sin \left( \dfrac{\pi}{2}-\alpha\right)+ \cos \left( \dfrac{\pi}{2}+\alpha \right) \end{equation} [/MATH]3)
[MATH] \begin{equation} \\tan \left( \pi + \alpha\right) + \cot \left( \pi - \alpha \right) \end{equation} [/MATH]
Prove the following identity:

[MATH] \begin{equation} \dfrac{1+tan(x)}{1-tan(x)}=\dfrac{cos(x)+sin(x)}{cos(x)-sin(x)} \end{equation} [/MATH]

 

[skeeter]

Trigonometry equations and identities help

Hello! I would be very happy if someone could help me with these exercises. (for questions 1-3) Let alpha be an acute angle. Suppose that cos alpha = 3/4. Compute: 1) \begin{equation} 3 cos(2\alpha) + 2 \end{equation} 2) \begin{equation} \\sin \left( \dfrac{\pi}{2}-\alpha\right)+ \cos...

mathhelpforum.com

 

[Deleted member 4993]

Hello! I would be very happy if someone could help me with these exercises.

(for questions 1-3)
Let alpha be an acute angle. Suppose that cos alpha = 3/4. Compute:

1)
[MATH] \begin{equation} 3 cos(2\alpha) + 2 \end{equation} [/MATH]2)
[MATH] \begin{equation} \\sin \left( \dfrac{\pi}{2}-\alpha\right)+ \cos \left( \dfrac{\pi}{2}+\alpha \right) \end{equation} [/MATH]3)
[MATH] \begin{equation} \\tan \left( \pi + \alpha\right) + \cot \left( \pi - \alpha \right) \end{equation} [/MATH]
Prove the following identity:

[MATH] \begin{equation} \dfrac{1+tan(x)}{1-tan(x)}=\dfrac{cos(x)+sin(x)}{cos(x)-sin(x)} \end{equation} [/MATH]

Start with #1 and use:

cos(2α) = 2 * cos²(α) - 1

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING​

Please share your work/thoughts about these problems.

 

[Steven G]

These are all fun problems to do. I can't wait to help you! The problem is that you failed to state what you need help with. It is extremely hard to help you if we have no idea where you need help. Possibly you know how to start these problems but get stuck in the middle so giving you help to the start the problem will not be very helpful.

 

[bloodborne]

Thank you for your help and your replies!

Im terribly sorry i wasnt being precise regarding what i needed help with.
We have had a few classes on trig but in my opinion not enough to solve these problems, so i would love to get help with how to start and further reasoning as what i should be looking for in these problems.

Thank you again

 

[skeeter]

Thank you for your help and your replies!

Im terribly sorry i wasnt being precise regarding what i needed help with.
We have had a few classes on trig but in my opinion not enough to solve these problems, so i would love to get help with how to start and further reasoning as what i should be looking for in these problems.

Thank you again

What, specifically, was lacking from the linked post in response #2 ?

 

[Deleted member 4993]

Thank you for your help and your replies!

Im terribly sorry i wasnt being precise regarding what i needed help with.
We have had a few classes on trig but in my opinion not enough to solve these problems, so i would love to get help with how to start and further reasoning as what i should be looking for in these problems. Thank you again

We gave you a hint to start #1 (response #3)?

What did you get when you used that "hint"?

Please show us your work!