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If 4cos^(2)x=3 and x is an acute angle, ...

If `4cos^(2)x=3 and x` is an acute angle, find the value of :
`cos^(2)x+cot^(2)x`

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To solve the problem, we need to find the value of \( \cos^2 x + \cot^2 x \) given that \( 4 \cos^2 x = 3 \) and \( x \) is an acute angle. ### Step-by-Step Solution: 1. **Start with the given equation:** \[ 4 \cos^2 x = 3 \] 2. **Isolate \( \cos^2 x \):** \[ \cos^2 x = \frac{3}{4} \] 3. **Find \( \cos x \):** \[ \cos x = \sqrt{\frac{3}{4}} = \frac{\sqrt{3}}{2} \] Since \( x \) is an acute angle, we take the positive root. 4. **Determine \( \cot x \):** We know that: \[ \cot x = \frac{\cos x}{\sin x} \] To find \( \sin^2 x \), we use the identity \( \sin^2 x + \cos^2 x = 1 \): \[ \sin^2 x = 1 - \cos^2 x = 1 - \frac{3}{4} = \frac{1}{4} \] Thus, \[ \sin x = \sqrt{\frac{1}{4}} = \frac{1}{2} \] 5. **Calculate \( \cot^2 x \):** \[ \cot x = \frac{\cos x}{\sin x} = \frac{\frac{\sqrt{3}}{2}}{\frac{1}{2}} = \sqrt{3} \] Therefore, \[ \cot^2 x = (\sqrt{3})^2 = 3 \] 6. **Combine \( \cos^2 x \) and \( \cot^2 x \):** \[ \cos^2 x + \cot^2 x = \frac{3}{4} + 3 \] To add these, convert \( 3 \) into a fraction with a denominator of \( 4 \): \[ 3 = \frac{12}{4} \] Thus, \[ \cos^2 x + \cot^2 x = \frac{3}{4} + \frac{12}{4} = \frac{15}{4} \] ### Final Answer: \[ \cos^2 x + \cot^2 x = \frac{15}{4} \]
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(C)
  1. Solve for x : sin^(2)60^(@)+cos^(2)(3x-9^(@))=1

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  2. If 4cos^(2)x=3 and x is an acute angle, find the value of : x

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  3. If 4cos^(2)x=3 and x is an acute angle, find the value of : cos^(2)x...

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  4. If 4cos^(2)x=3 and x is an acute angle, find the value of : cos3x

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  5. If 4cos^(2)x=3 and x is an acute angle, find the value of : sin2x

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  6. In DeltaABC, angleB=90^@), AB=y" units", BC=sqrt(3) " units", AC = 2 u...

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  7. In DeltaABC, angleB=90^@), AB=y" units", BC=sqrt(3) " units", AC = 2 u...

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  8. In DeltaABC, angleB=90^@), AB=y" units", BC=sqrt(3) " units", AC = 2 u...

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  9. In DeltaABC, angleB=90^@), AB=y" units", BC=sqrt(3) " units", AC = 2 u...

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  10. If 2cos(A+B)=2sin(A-B)=1, find the values of A and B.

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  11. Solve the following equations for A, if : 2sinA=1

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  12. Solve the following equations for A, if : 2cos2A=1

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  13. Solve the following equations for A, if : sin3A=sqrt(3)/2

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  14. Solve the following equations for A, if : sec2A=2

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  15. Solve the following equations for A, if : sqrt(3)tanA=1

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  16. Solve the following equations for A, if : tan3A=1

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  17. Solve the following equations for A, if : 2sin3A=1

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  18. Solve the following equations for A, if : sqrt(3)cot2A=1

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  19. Calculate the value of A, if : (sinA-1)(2cosA-1)=0

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  20. Calculate the value of A, if : (tanA-1)(cosec3A-1)=0

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