College of Admission Tests Multan

Trigonometric Functions

Solve the question of and select the option from the choices A through D/E. Check your Answer and view the explanation.

Question: 2

If sin(x)=0.5, what is sin(8x) if x is between 0 and 2π?
  • −0.5
  • -√3/2
  • 3/2
  • 0.5
  • -1.5

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Correct Answer: B

We know that sin(π/6) = 0.5

Therefore, we are looking for sin(8 × π/6) or sin(4π/3)

Now, this has a reference angle of π/3, but it is in the third quadrant. This means that the value will be negative. The value of sin(π/3) is √3/2

However, given the quadrant of our angle, it will be -√3/2