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  1. If sin 17° = (x / y) , then sec 17° – sin 73° is equal to
    1. y
      y² - x²
    2. x(y² - x²)
    3. x
      (y² - x²)
    4. y(y² - x²)
Correct Option: D

sin 17° =
x
y

sin 73° = sin (90° – 17°)
= cos 17°
∴ cos 17° = √1 - sin² 17°

=
y² - x²
y

∴ sec 17° =
y
y² - x²

∴ sec 17° – sin 73°
= sec 17° – cos 17°
y
-
y² - x²
y² - x²y

=
y² - (y² - x²)
y√y² - x²

=
y² - y² + x²
y√y² - x²

=
y
y√y² - x²



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