Question
Mathematics Question on Trigonometric Identities
Let θ∈(0,4π)andt1=(tanθ)tanθ,t2=(tanθ)cotθ,t3=(cotθ)tanθandt4=(cotθ)cotθ,then
A
t1>t2>t3>t4
B
t4>t3>t1>t2
C
t3>t1>t2>t4
D
t2>t3>t1>t4
Answer
t4>t3>t1>t2
Explanation
Solution
The correct option is:(B): t 4>t 3>t 1>t 2.
Given: t 1=tan θ tan θ
This implies: log t 1=tan θ log(tan θ)=tan θ log(cot θ)
Which further leads to: t 1=−(cot θ tan θ)
Thus: t 2 and �1>�2 t 1>t 2
Similarly, t 4=cot θ cot θ
This implies: log log t 4=cot θ log(cot θ)=cot θ log(tan θ)
Which further leads to: t 4=−(cot θ tan θ)
Thus: t 4=− t 3 and t 4>t 3
In the range θ ∈(0,24 π ),cotθ>tanθ
⇒ t4>t3>t1>t2.
Therefore, (b) is the answer.