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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 :
`sin2x`

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The correct Answer is:
To solve the problem step by step, we start with the given equation: **Step 1: Start with the equation.** Given: \[ 4 \cos^2 x = 3 \] **Step 2: Isolate \(\cos^2 x\).** Divide both sides by 4: \[ \cos^2 x = \frac{3}{4} \] **Step 3: Take the square root.** Taking the square root of both sides gives: \[ \cos x = \sqrt{\frac{3}{4}} \] Since \(x\) is an acute angle, we only consider the positive root: \[ \cos x = \frac{\sqrt{3}}{2} \] **Step 4: Identify the angle \(x\).** We know that: \[ \cos 30^\circ = \frac{\sqrt{3}}{2} \] Thus, we can conclude: \[ x = 30^\circ \] **Step 5: Find \(2x\).** Now, we need to find \(2x\): \[ 2x = 2 \times 30^\circ = 60^\circ \] **Step 6: Calculate \(\sin 2x\).** Now we calculate: \[ \sin 2x = \sin 60^\circ \] We know that: \[ \sin 60^\circ = \frac{\sqrt{3}}{2} \] **Final Answer:** Thus, the value of \(\sin 2x\) is: \[ \sin 2x = \frac{\sqrt{3}}{2} \] ---
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(C)
  1. If 4cos^(2)x=3 and x is an acute angle, find the value of : cos^(2)x...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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  19. Calculate the value of A, if : (sec2A-1)(cosec3A-1)=0

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  20. Calculate the value of A, if : cos3A.(2sin2A-1)=0

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