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Tamil Nadu Board of Secondary EducationHSC Science Class 11

Find the principal solution and general solution of the following:sin θ = -12 - Mathematics

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Question

Find the principal solution and general solution of the following:
sin θ = `-1/sqrt(2)`

Sum
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Solution

sin θ = `-1/sqrt(2)`

We know that principal of sin θ lies in `[ - pi/2, pi/2]`

sin θ = `- 1/sqrt(2 < 0`

∴ The principal value of sin θ lies in the IV quadrant.

sin θ = `- 1/sqrt(2)`

= `- sin(pi/4)`

sin θ = `sin (- pi/4)`

Hence θ = `- pi/4` is the principal solution.

The general solution is

θ = nπ + (– 1)n . `( pi/4)`, n ∈ Z

θ = `"n"pi + (- 1)^("n" + 1) * pi/4`, n ∈ Z

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Chapter 3: Trigonometry - Exercise 3.8 [Page 133]

APPEARS IN

Samacheer Kalvi Mathematics - Volume 1 and 2 [English] Class 11 TN Board
Chapter 3 Trigonometry
Exercise 3.8 | Q 1. (i) | Page 133

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