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Grade 1010 grade maths

From trignometry of maths we can use the basic formula required for it.

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Profile image of Sandesh
6 Years agoGrade 10
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1 Answer

Profile image of Arun
ApprovedApproved Tutor Answer6 Years ago
Dear student
 
As tan60 = √3
Niw main thing we have ti find out is
tan 6 tan 42 tan 78 (tan18)/ tan18
 
 = tan 6 tan (90 -18) tan (60+18) tan 18 /tan18
 
Use formula tan A tan (60-A) tan(60+A) = tan3A
 
 = tan 6 tan54 /tan18
 
 = tan 6 tan (60-6) tan(60+6) /tan 18 tan 66
 
 = Tan 18/tan 18 tan 66
 
 = 1/tan 66
 
Hence answer will be
√3 /tan66
 
Means I think you have typed wring as it should be tan66 instead of tan60