CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

Show that tan113+tan115=12cos13365

Open in App
Solution

To prove:- tan113+tan115=12cos13365
Proof:-
tan113+tan115
As we know that,
tan1x+tan1y=tan1(x+y1xy)
Therefore,
tan113+tan115=12cos13365
tan1⎜ ⎜ ⎜13+1511315⎟ ⎟ ⎟=12cos13365
tan1⎜ ⎜ ⎜5+31515115⎟ ⎟ ⎟=12cos13365
tan1(814)=12cos13365
2tan1(47)=cos13365
tan1⎜ ⎜ ⎜ ⎜2×471(47)2⎟ ⎟ ⎟ ⎟=cos13365
tan1⎜ ⎜ ⎜87491649⎟ ⎟ ⎟=cos13365
tan15633=cos13365
cos13365=cos13365(tan15633=cos13365)
L.H.S. = R.H.S.
Hence proved.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Trigonometric Identities_Concept
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon