Trignometric equations

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.

Trignometric equations

Postby huriah on Thu Apr 24, 2014 12:56 am

Hi,
First of all thanks for your reply. Here is another question about trigonometric equation.
Solved Example:
cos^(x) + cos (x)= sin^x on 0 degree < x< 360
cos^(x) + cos (x)= 1-cos^(x)
2cos ^(x) + cos (x)-1= 0
(2cos(x) -1)(cos(x) + 1= 0
cos(x)=1/2 , cos x = -1
so complete solution is
60 degree,180 degree, 300 degree. :confused:
AS from reference angle , I know that cos 1/2 = 60 degree .But how did the book get the complete solution like 180 and 300 degree .(from where came the 180 and 300 degree)
huriah
 
Posts: 7
Joined: Thu Mar 20, 2014 5:36 pm

Sponsor

Sponsor
 

Postby stapel_eliz on Thu Apr 24, 2014 10:12 am

huriah wrote:cos^(x) + cos (x)= sin^x on 0 degree < x< 360

The powers (the numbers after the exponentiation symbol "^") are missing. Please reply with that information.

huriah wrote:I know that cos 1/2 = 60 degree .But how did the book get the complete solution like 180 and 300 degree .

From the form and behavior of the cosine wave; in particular, in how the cosine wave repeats values, due to its periodic nature. :wink:
User avatar
stapel_eliz
 
Posts: 1720
Joined: Mon Dec 08, 2008 4:22 pm


Return to Trigonometry

cron