Test Index

NCERT Class XI Mathematics - Trigonometric Functions - Solutions

© examsnet.com
Question : 34
Total: 61
sin5x+sin3x
cos5x+cos3x
 = tan 4x
Solution:  
We have, L.H.S.=
sin5x+sin3x
cos5x+cos3x
=
2sin(
5x+3x
2
)cosx(
5x−3x
2
)
2cos(
5x+3x
2
)cos(
5x−3x
2
)
 =
2sin4xcosx
2cos4xcosx
 = tan 4x = R.H.S.
© examsnet.com
Go to Question:
Prev Question
Next Question