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If Cos x/2 = 12/13 and X lies in Quadrant I, find the values of

(i) sin x 

(ii) cos x 

(iii) cot x

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Given: cos\(\frac{x}{2}\) = \(\frac{12}{13}\) and x lies in Quadrant I i.e, All the trigonometric ratios are

positive in I quadrant

To Find: 

(i) sin x 

(ii) cos x 

(iii) cot x

We have, sin x = \(\sqrt{1-cos^2\text{x}}\)

We know that, cos\(\frac{x}{2}\) = \(\sqrt{\frac{1+cosx}{2}}{}\)

(∵ cosx is positive in | quadrant)

Since, sinx = \(\sqrt{1-cos^2\text{x}}\)

Hence, we have sinx = \(\frac{120}{169}.\)

(ii) cosx

Formula used:

We know that, cos\(\frac{x}{2}\) = \(\sqrt{\frac{1+cosx}{2}}{}\)

(∵ cosx is positive in | quadrant)

(iii) cotx

Formula used:

Hence, we have cotx = \(\frac{119}{120}\)

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