Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

hartnn Group TitleBest ResponseYou've already chosen the best response.2
use the relation, \(\Large \sin^2A+\cos^2A=1\) to get a quadratic equation in only cos A
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
How's that @hartnn I really dont know
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
2sin^2A + cosA + 1 = 0 2 (1 cos^2 A) +cos A +1 =0 did u get this?
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
Yes. Got that part Then what? @hartnn
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
right, now thats an quadratic equation in cos A. imagine you put cos A = x 2(1x^2)+x+1 =0 can you bring that in the form of ax^2+bx+c=0 ?
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
Okay. Will it be 2x^2+x+3 ? @hartnn
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
yes, or you can write that as 2x^2x3=0 too can you solve this quadratic?
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
I dont know for cosA=3/2 ??? But for cos A=1 A={180} It it correct? @hartnn
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
if you need solutions in the range 0 to 360, then yes, A = 180 is correct. else, the general form will be A = 180 \(\pm\) 360n
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
as for cos A = 3/2 recollect that cos A can never be greater than 1 as the range of cos function is 1 to 1 so, cos A = 3/2 will have no solution :)
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
else, the general form will be A = 180 ± 360n What does that mean??? ^ So A is just 180 nothing else? @hartnn
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
with cos A = 1 you got A = 180, right ? what about when A = 180+360 = 540 ? is cos 540 also = 1 ? if yes, why don't you consider it as a solution ? similarly for 180360,180+2*360, 1802*360 and so on (we don't consider them as the solution only when it is given that the range of A is from 0 to 360....and in that case only 180 is your answer :) )
 7 months ago

kaylala Group TitleBest ResponseYou've already chosen the best response.1
Okay. I see. Thank you
 7 months ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
welcome ^_^
 7 months ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.