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  1. If sec θ + tan θ = &radic3 (0° ≤ θ ≤ 90°), then tan 3θ is
    1. undefined
    2. 1
      3
    3. 1
      2

    4. 3
Correct Option: A

sec θ + tan θ = √3.....(i)
∵ sec² θ - tan² θ = 1
⇒ (secθ - tanθ )(secθ + tanθ ) = 1

⇒ secθ - tanθ =
1
....(ii)
3

By subtracting (ii) from (i)
secθ + tanθ - secθ + tanθ
= √3 -
1
3

⇒ 2tan θ =
3 - 1
3

= tan θ =
1
= tan 30°
3

⇒ θ = 30°
∴ tan3 θ =tan 90° = undefined



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