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What's the answer to 4sin(theta)=3cos(theta), and how do you get there? Thanks!

 Feb 7, 2015

Best Answer 

 #2
avatar+130477 
+10

There are two solutions on [0, 2pi]

One occurs at about (36.9, 2.4)  and the other at about (216.9, -2.4)

These solutions repeat on every 2pi interval

Here's the graph......https://www.desmos.com/calculator/xvemw185zj

 

 Feb 7, 2015
 #1
avatar+118703 
+5

4sin(theta)=3cos(theta)

 

4sin(θ)=3cos(θ)sinθcosθ=34tanθ=0.75θ=atan(0.75)

 

tan3601(0.75)=36.869897645844

 Feb 7, 2015
 #2
avatar+130477 
+10
Best Answer

There are two solutions on [0, 2pi]

One occurs at about (36.9, 2.4)  and the other at about (216.9, -2.4)

These solutions repeat on every 2pi interval

Here's the graph......https://www.desmos.com/calculator/xvemw185zj

 

CPhill Feb 7, 2015
 #3
avatar+118703 
0

Thanks Chris. 

Never forget that there is often more than one solution with trigonometry. :)

You would think I should have learned this lesson by now - I guess I haven't.  :))

 Feb 7, 2015

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