Flag Trigonometry> Trigonometric equations...
question mark

f(x) = sin x + cos x, then find the most general solution of

f(x) = [f(pi/10)]. [.] is greatest integer function

iit jee , 15 Years ago
Grade 12
anser 1 Answers
Badiuddin askIITians.ismu Expert

Last Activity: 15 Years ago

Dear

f(pi/10) =sin18 + cos18

                 =√2 sin(45+18) =√2sin63

we know sin63>sin45=1/√2 

and sin63 <1

so     1<√2sin63<2

 so [√2sin63] =1

 

now equation become 

sinx +cosx =1

cos(x-∏/4) =1/√2

cos(x-∏/4) =cos∏/4

 x-∏/4 =2n∏ ± ∏/4

 x =∏/4 +2n∏ ± ∏/4

x = 2n∏ and 2n∏ +∏/2

Please feel free to post as many doubts on our discussion forum as you can.
If you find any question Difficult to understand - post it here and we will get you
the answer and detailed  solution very  quickly.

 We are all IITians and here to help you in your IIT JEE preparation.

All the best.
 
Regards,
Askiitians Experts
Badiuddin

 

Provide a better Answer & Earn Cool Goodies

star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free