Solving for cosine using multiple angles

👉 Learn how to solve trigonometric equations. There are various methods that can be used to evaluate trigonometric equations, they include by factoring out the GCF and simplifying the factored equation. Another method is to use a trigonometric identity to reduce and then simplify the given equation. Simpler trigonometric equations involving one trigonometric function can simply be solved by inverse operations.

When solving a trigonometric equation it is usually useful to identify which method best evaluates the given equation and apply the method. Because trigonometric functions are sinusoidal in nature (continuous and repetitive), a trigonometric equation may contain many solutions depending on the domain of consideration.

When the trigonometric equation involves multiple angles, the trigonometric equation is evaluated first, and then the multiple of the angle is then divided through the obtained answer.

Organized Videos:
✅ Solve Trigonometric Equations
✅ Solve Trigonometric Equations by Factoring GCF
✅ Solve Trigonometric Equations by Zero Product Property
✅ Solve Trigonometric Equations by Factoring
✅ Solve Trigonometric Equations by Taking the Square Root
✅ Solve a Trig Equation with Half Angles
✅ Solve a Trigonometric Equations with Multi Angles Squared
✅ Solve Trigonometric Equations all Solutions and on an Interval
✅ Solve Trigonometric Equations with Multi Angles
✅ Solve Trigonometric Equations Learn About

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#analytictrig #brianmlogan

[theartistkat]

I’ve been working on the same problem for over an hour and this video made me solve it instantly, thank you!

[drbadnws]

As someone whose also named Brian, I identify deeply with your lectures. I’m binge watching your trig videos before my final tomorrow. Thanks for the content, Brian.
-Brian

[YukamsGaming]

well, when even a teacher can struggle to these kind of exercises, it means you'll have to work very hard and be very prudent when doing some trigonometry. Thanks for the video, it helped !

[yeahimawesome]

i think it's incorrect. it's a positive cosine, which means it will be in quadrant 1 and 4, so the answers should be π/6 + 2πn and 11π/6 + 2πn

[tb]

my man mr. mclogan coming in clutch throughout highschool and now in college when i'm taking calc 3 and need a quick refresher... lol thank you so much man. you've always made helpful videos for me.

[emeister]

thanks now i understand the "+ 2πn"

[MadAustinite]

Thank you for drawing that out! Helped a lot to visualize it

[engmahasabah]

Find integral of area sinx.sin2x-cosx.cos2x

[Justin-srwq]

Cos(1/2) equals Pi/3 and 5pi/3. Not 2pi/3, cosine equals -1/2 at 2pi/3. Am I missing something?

[michealadebunmi]

I came from d future and dis was really helpful thanks SIR

[tsholofelo]

can u plz explain fully to me, where does that 2/pie nd pie/3 come from after solving the equation nd how I memories them so that I can remember them easily

[mbenitez]

Okay I have a huge problem with Cosines.
What you have taught I learned in my text book 5.4 but I'm looking at 5.5 and it gives me similar problems
except they specify formulas, sine and tangent have their one unique one except for some reason the cosine has 3.

Cos2U= Cos^2u - Sin^2u
Cos2U= 2Cos^2u -1
Cos2U= 1-2sin^2u

how and why is this?
Edit: added the u's (I always forget them lol)

[jeyhuntalibov]

why it is 5p/3? shouldn't it be 2p/3?

[ariv]

Since there is a 2x wouldn’t you need to go around the unit circle 2 more times so you would have 4 answers in total?

[raafiagul]

thanks for the explanation.. yours are always helpful.

[sidrakhan]

Sir, can you please solve this question 2sin^2( x) +√3sin(x)-3>0

[michellec.]

My prof. said it was pi/6, 5pi/6, 7pi/6, 11pi/6 why is this?