alexh107
  • alexh107
Trig equations help: Find all solutions in the interval [0, 2π). cos x = sin x Really in need of help with this concept so if anyone can explain it to me it would be very appreciated.
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
chestercat
  • chestercat
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
anonymous
  • anonymous
look on the unit circle to see where the first and second coordinates are the same you got a unit circle cheat sheet?
anonymous
  • anonymous
anonymous
  • anonymous
cosine is the first coordinate, sine is the second there are two points on the unit circle where the first and second coordinates are the same it is on the last page1

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

alexh107
  • alexh107
Okay one second I'm looking at it now.
alexh107
  • alexh107
I'm not really sure which two points on the circle have the same first and second coordinates. Each quadrant make a different coordinate negative/positive so isn't that impossible?
jim_thompson5910
  • jim_thompson5910
hint: look in quadrant 1 and quadrant 3
alexh107
  • alexh107
Is it pi/4 and 5pi/4? I feel like it's really obvious but I'm just not seeing it.
jim_thompson5910
  • jim_thompson5910
yep
1 Attachment
alexh107
  • alexh107
Would that be the final answer then?
jim_thompson5910
  • jim_thompson5910
you just said them both: pi/4 and 5pi/4
jim_thompson5910
  • jim_thompson5910
cos(pi/4) = sqrt(2)/2 sin(pi/4) = sqrt(2)/2 this is shown at the point in Q1 with both coordinates equal to sqrt(2)/2
jim_thompson5910
  • jim_thompson5910
cos(5pi/4) = -sqrt(2)/2 sin(5pi/4) = -sqrt(2)/2 this is shown at the point in Q3 with both coordinates equal to -sqrt(2)/2
alexh107
  • alexh107
Oh okay, thank you so much!
jim_thompson5910
  • jim_thompson5910
I guess another way to do it is to square both sides and use an identity sin(x) = cos(x) sin^2(x) = cos^2(x) sin^2(x) = 1-sin^2(x) sin^2(x)+sin^2(x) = 1 2*sin^2(x) = 1 keep going to solve for x You'll have to check the possible solutions (some possible solutions will be extraneous)
jim_thompson5910
  • jim_thompson5910
no problem
alexh107
  • alexh107
That makes a lot of sense too, thank you!

Looking for something else?

Not the answer you are looking for? Search for more explanations.