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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 :
x

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To solve the equation \(4 \cos^2 x = 3\) for \(x\) where \(x\) is an acute angle, we can follow these steps: ### Step 1: Rewrite the equation Start with the given equation: \[ 4 \cos^2 x = 3 \] ### Step 2: Isolate \(\cos^2 x\) Divide both sides of the equation by 4: \[ \cos^2 x = \frac{3}{4} \] ### Step 3: Take the square root Now, take the square root of both sides. Since \(x\) is an acute angle, we only consider the positive root: \[ \cos x = \sqrt{\frac{3}{4}} = \frac{\sqrt{3}}{2} \] ### Step 4: Identify the angle We know from trigonometric ratios that: \[ \cos 30^\circ = \frac{\sqrt{3}}{2} \] Thus, we can equate: \[ x = 30^\circ \] ### Step 5: Verify the angle Since \(30^\circ\) is indeed an acute angle (between 0 and 90 degrees), we confirm that our solution is valid. ### Final Answer \[ x = 30^\circ \] ---
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(C)
  1. Solve for x : cos^(2)30^(@)+sin^(2)2x=1

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  2. Solve for x : sin^(2)60^(@)+cos^(2)(3x-9^(@))=1

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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