hermom1967
  • hermom1967
Please help explain what I did wrong Express the complex number in trigonometric form. -2i
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!
hermom1967
  • hermom1967
I got 2(cos 90° + i sin 90°) but that was wrong and I don't understand why.
hermom1967
  • hermom1967
@satellite73
myininaya
  • myininaya
ok cos(90 deg)=0 and sin(90 deg)=1 so you have 2(0+i*1) 2(i*1) 2(i) 2i

Looking for something else?

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

More answers

myininaya
  • myininaya
but you wanted -2i
myininaya
  • myininaya
why don't you just change 2 to -2
myininaya
  • myininaya
or you could go with changing the angle from 90 deg to 270 deg since sin will be negative 1there
myininaya
  • myininaya
let me know if you need more assistance @hermom1967
hermom1967
  • hermom1967
So it would be 2(cos 270° + i sin 270°)?
hermom1967
  • hermom1967
Is that because it's in a different quadrant?
myininaya
  • myininaya
right since cos(270 deg)=0 and sin(270 deg)=-1 so you would have 2(0+i[-1]) =2[i[-1]] =2[-i] =-2i
myininaya
  • myininaya
also have you ever graphed things in the form a+bi?
hermom1967
  • hermom1967
No
myininaya
  • myininaya
we have a is 0 which means we don't go left or right any but b is -2 which means we have to go down 2 units
myininaya
  • myininaya
|dw:1432867663223:dw|
hermom1967
  • hermom1967
Okay, I understand that
myininaya
  • myininaya
you can think of a+bi as if you are plotting points (a,b)
myininaya
  • myininaya
you know when graphing
myininaya
  • myininaya
|dw:1432867746418:dw|
myininaya
  • myininaya
and yeah you could have chose the angle to be 90 deg if you made r negative like you could have done -2(cos(90)+isin(90))
hermom1967
  • hermom1967
Okay, thank you so much! Now to be able to retain that... LOL
myininaya
  • myininaya
I think it will get a little easier when you guys go over plotting things in form a+bi or plotting also polar coordinates, you know where you plot things in the form (r,theta)

Looking for something else?

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