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Find the value of : cosec^(2)60^(@)-ta...

Find the value of :
`cosec^(2)60^(@)-tan^(2)30^(@)`

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To solve the problem, we need to find the value of \( \csc^2 60^\circ - \tan^2 30^\circ \). ### Step-by-step Solution: 1. **Identify the trigonometric identities**: \[ \csc^2 \theta = \frac{1}{\sin^2 \theta} \] \[ \tan \theta = \frac{\sin \theta}{\cos \theta} \] Therefore, \[ \tan^2 \theta = \frac{\sin^2 \theta}{\cos^2 \theta} \] 2. **Substitute the angles into the identities**: \[ \csc^2 60^\circ = \frac{1}{\sin^2 60^\circ} \] \[ \tan^2 30^\circ = \frac{\sin^2 30^\circ}{\cos^2 30^\circ} \] 3. **Find the values of \( \sin 60^\circ \), \( \sin 30^\circ \), and \( \cos 30^\circ \)**: - \( \sin 60^\circ = \frac{\sqrt{3}}{2} \) - \( \sin 30^\circ = \frac{1}{2} \) - \( \cos 30^\circ = \frac{\sqrt{3}}{2} \) 4. **Calculate \( \csc^2 60^\circ \)**: \[ \csc^2 60^\circ = \frac{1}{\left(\frac{\sqrt{3}}{2}\right)^2} = \frac{1}{\frac{3}{4}} = \frac{4}{3} \] 5. **Calculate \( \tan^2 30^\circ \)**: \[ \tan^2 30^\circ = \frac{\left(\frac{1}{2}\right)^2}{\left(\frac{\sqrt{3}}{2}\right)^2} = \frac{\frac{1}{4}}{\frac{3}{4}} = \frac{1}{3} \] 6. **Substitute the values back into the expression**: \[ \csc^2 60^\circ - \tan^2 30^\circ = \frac{4}{3} - \frac{1}{3} = \frac{4 - 1}{3} = \frac{3}{3} = 1 \] ### Final Answer: \[ \csc^2 60^\circ - \tan^2 30^\circ = 1 \]
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(A)
  1. Find the value of : tan30^(@)tan60^(@)

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  2. Find the value of : cos^(2)60^(@)+sin^(2)30^(@)

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  3. Find the value of : cosec^(2)60^(@)-tan^(2)30^(@)

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  4. Find the value of : sin^(2)30^(@)+cos^(2)30^(@)+cot^(2)45^(@)

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  5. Find the value of : cos^(2)60^(@)+sec^(2)30^(@)+tan^(2)45^(@)

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  6. Find the value of : tan^(2)30^(@)+tan^(2)45^(@)+tan^(2)60^(@)

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  7. Find the value of : (tan45^(@))/(cosec30^(@))+(sec60^(@))/(cot45^(@)...

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  8. Find the value of : 3sin^(2)30^(@)+2tan^(2)60^(@)-5cos^(2)45^(@)

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  9. Prove that : sin60^(@)cos30^(@)+cos60^(@).sin30^(@)=1

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  10. Prove that : cos30^(@).cos60^(@)-sin30^(@).sin60^(@)=0

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  11. Prove that : cosec^(2)45^(@)-cot^(2)45^(@)=1

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  12. Prove that : cos^(2)30^(@)-sin^(2)30^(@)=cos60^(@)

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  13. Prove that : ((tan60^(@)+1)/(tan60^(@)-1))^(2)=(1+cos30^(@))/(1-cos3...

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  14. Prove that : 3cosec^(2)60^(@)-2cot^(2)30^(@)+sec^(2)45^(@)=0.

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  15. Prove that : sin(2 times 30^(@))=(2tan30^(@))/(1+tan^(2)30^(@))

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  16. Prove that : cos(2 times 30^(@))=(1-tan^(2)30^(@))/(1+tan^(2)30^(@))

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  17. Prove that : tan(2 times 30^(@))=(2tan30^(@))/(1-tan^(2)30^(@))

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  18. ABC is an isosceles right-angled triangle. Assuming AB = BC = x, find ...

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  19. Prove that : sin60^(@)=2sin30^(@)cos30^(@).

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  20. Prove that : 4(sin^(4)30^(@)+cos^(4)60^(@))-3(cos^(2)45^(@)-sin^(2)...

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