tan2B=cotB-18
2B is acute angle find the value of B
rishimhaske:
is it cot(B-18) or cotB- 18
cot(B-18)
hmm
The answer is 36 degree
Answers
Answered by
0
tan2B=cot(B-18
since
tan(90-Ф)=cotФ
so
tan2B=tan(90-B+18)
so
2B=108-B
B=36
Answered by
2
Cot (B-18) = Tan (90 - (B - 18)) = Tan (108 - B)
Tan 2B = Tan (108 - B) => there are multiple possibilities.
1) 2 B = 108 - B => 3 B = 108 => B = 36°
2) 2 B = 180 + 108 - B => 3 B = 288 => B = 96°
or, 180 + 2B = 108 -B => B = - 24°
As 2B is an acute angle, we choose only the 1st one. B = 36°
Tan 2B = Tan (108 - B) => there are multiple possibilities.
1) 2 B = 108 - B => 3 B = 108 => B = 36°
2) 2 B = 180 + 108 - B => 3 B = 288 => B = 96°
or, 180 + 2B = 108 -B => B = - 24°
As 2B is an acute angle, we choose only the 1st one. B = 36°
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