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Find the values of: (i) tan (-30^(@)) ...

Find the values of:
(i) `tan (-30^(@))` (ii) `sin 120^(@)` (iii) `sin 135^(@)` (iv) `cos 150^(@)` (v) `sin 270^(@)` (vi) `cos 270^(@)`

A

`120^(@)`

B

`pi/3 rad`

C

`(2pi)/3 rad`

D

`160^(@)`

Text Solution

AI Generated Solution

The correct Answer is:
To find the values of the trigonometric functions given in the question, we will solve each part step by step. ### Solution: **(i) Find `tan(-30°`:** Using the property of tangent: \[ \tan(-\theta) = -\tan(\theta) \] So, \[ \tan(-30°) = -\tan(30°) \] We know that: \[ \tan(30°) = \frac{1}{\sqrt{3}} \] Thus, \[ \tan(-30°) = -\frac{1}{\sqrt{3}} \] **(ii) Find `sin(120°)`:** We can express \(120°\) as: \[ 120° = 90° + 30° \] Using the sine addition formula: \[ \sin(90° + \theta) = \cos(\theta) \] So, \[ \sin(120°) = \cos(30°) \] And we know: \[ \cos(30°) = \frac{\sqrt{3}}{2} \] Thus, \[ \sin(120°) = \frac{\sqrt{3}}{2} \] **(iii) Find `sin(135°)`:** We can express \(135°\) as: \[ 135° = 90° + 45° \] Using the sine addition formula: \[ \sin(90° + \theta) = \cos(\theta) \] So, \[ \sin(135°) = \cos(45°) \] And we know: \[ \cos(45°) = \frac{1}{\sqrt{2}} \] Thus, \[ \sin(135°) = \frac{1}{\sqrt{2}} \] **(iv) Find `cos(150°)`:** We can express \(150°\) as: \[ 150° = 180° - 30° \] Using the cosine subtraction formula: \[ \cos(180° - \theta) = -\cos(\theta) \] So, \[ \cos(150°) = -\cos(30°) \] And we know: \[ \cos(30°) = \frac{\sqrt{3}}{2} \] Thus, \[ \cos(150°) = -\frac{\sqrt{3}}{2} \] **(v) Find `sin(270°)`:** We can express \(270°\) as: \[ 270° = 180° + 90° \] Using the sine addition formula: \[ \sin(180° + \theta) = -\sin(\theta) \] So, \[ \sin(270°) = -\sin(90°) \] And we know: \[ \sin(90°) = 1 \] Thus, \[ \sin(270°) = -1 \] **(vi) Find `cos(270°)`:** We can express \(270°\) as: \[ 270° = 180° + 90° \] Using the cosine addition formula: \[ \cos(180° + \theta) = -\cos(\theta) \] So, \[ \cos(270°) = -\cos(90°) \] And we know: \[ \cos(90°) = 0 \] Thus, \[ \cos(270°) = 0 \] ### Final Answers: 1. \( \tan(-30°) = -\frac{1}{\sqrt{3}} \) 2. \( \sin(120°) = \frac{\sqrt{3}}{2} \) 3. \( \sin(135°) = \frac{1}{\sqrt{2}} \) 4. \( \cos(150°) = -\frac{\sqrt{3}}{2} \) 5. \( \sin(270°) = -1 \) 6. \( \cos(270°) = 0 \)

To find the values of the trigonometric functions given in the question, we will solve each part step by step. ### Solution: **(i) Find `tan(-30°`:** Using the property of tangent: \[ ...
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