Question
If tan 2 α = 1 + 2tan 2 β, then
find the value of √2cos α – cos β = ?Solution
tan 2 α = 1+ 2 tan 2 β
put α = 60°, β = 45°, then, LHS, (√3) 2 = 1 + 2 (1) 2
⇒ 3 = 3 , Satisfied so, √2 cos α − cos β = √2 × (1/2) − 1/√2
= 1/√2 – 1/√2 = 0
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