Skip to main content
M

Major Spinka DVM

Feb 20, 2025

what is the solution set to cos2x=0?

thanks
0
Save

2 Answers

R
Raymond Moen

Feb 20, 2025

Cos(2x) = 2cos²(x) -1 So substituting this we get 2cos² (x) – 1 =0 Now solve as a regular equation, add 1, divide by 2, take the square root2cos² (x)= 1cos²(x)=1/2cos(x)= +/- √2/2So at what angle does cosine (x-value) equal -√2/2 and positive √2/2?45 degrees, 135, 225, 315 or use the ratio (180/pi) to convert to radian pi/4, 3pi/4, 5pi/4, 7pi/4Alternatively, you could have replaced 2x with Θ to getcos(Θ)=0Think where does theta equal 0, that would be at Θ=pi/2 + 2(pi)(k) and Θ=3pi/2 + 2(pi)(k) where k is a positive integer Next replace Θ with 2x2x=pi/2 + 2(pi)kSolve for x to getx=pi/4 + pi(k)x=3pi/4 + pi(k)Then just plug in for kWhen k=0, x= pi/4, 3pi/4k=1 x = 5pi/4, 7pi/4 and so on... Show More
0
R
Raymond Moen

Feb 20, 2025

In radians: cos (2x) = 0 –> 2x = pi/2, 3pi/2, …. so x = pi/4, 3pi/4, … In degrees cos(2x) = 0 –> 2x = 90, 270, 450, … so x = 45, 135, 225,…... Show More
0

Want to answer this question?

Join our community to share your knowledge!

Log in Sign up

Categories

Tags

Related Questions

2
2
What is the solution to the equation 93x ≈ 7?

What is the solution to the equation 93x ≈ 7?

1
What is the solution to the equation below, rounded to the

What is the solution to the equation below, rounded to the

1
What is the solution to this question?

A capacitor is connected across an oscillating emf with a peak current through the capacitor of 7.00 A. If the frequency...

7
what is the song called that Stifler dance to in American Pie: the wedding?

the song where he has a dance off with a 𝒈𝒶𝓎 guy

7
What is the song from Bully Beatdown when the MMA fighters come out?

It goes something like: I won’t go down without a fight…And no, it isn’t New Found Glory – Not Without a Fight, that isn...

4
What is the song from the newest windows 8 commercial?

had a dubstep feel but had singing too (Guy)appeared while i was watching walking dead if that helps at all

1
6
What is the song that plays in the movie Set It Off while CLEO( queen latifah) is getting shot by the cops.?

I looked at the soundtrack for the movie but it's not on there. The song is very slows and plays while the character Cle...

3