Home
Class 9
MATHS
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`

Text Solution

AI Generated Solution

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 to find \(\cos x\).** Since \(x\) is an acute angle, we take the positive square root: \[ \cos x = \sqrt{\frac{3}{4}} = \frac{\sqrt{3}}{2} \] **Step 4: Determine the angle \(x\).** From trigonometric values, we know: \[ \cos 30^\circ = \frac{\sqrt{3}}{2} \] Thus, \[ x = 30^\circ \] **Step 5: Find \(2x\).** Calculate: \[ 2x = 2 \times 30^\circ = 60^\circ \] **Step 6: Calculate \(\sin 2x\).** Now, we need to find: \[ \sin 2x = \sin 60^\circ \] From trigonometric values, we know: \[ \sin 60^\circ = \frac{\sqrt{3}}{2} \] **Final Answer:** Thus, the value of \(\sin 2x\) is: \[ \sin 2x = \frac{\sqrt{3}}{2} \] ---
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRICAL RATIOS OF STANDARD ANGLES

    ICSE|Exercise EXERCISE 23(B)|34 Videos
  • TRIGONOMETRICAL RATIOS

    ICSE|Exercise EXERCISE 22(B)|50 Videos
  • TRIGONOMETRY

    ICSE|Exercise TOPIC -4 ( COMPLEMENTARY ANGLES ) (4 MARKS QUESTIONS )|4 Videos

Similar Questions

Explore conceptually related problems

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

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

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

If 4 cos^(2) x = 3 and x is an acute angle find the value of : (i) x (ii) cos^(2)x + cot^(2)x (iii) cos 3x (iv) sin 2x

If cos 3x= 0 and x is acute find the value of : sin x

If sin2A=cos(A-12^(@))and2A is an acute angle , find the value of A.

If cos 3x= 0 and x is acute find the value of : cos 2x

If cos x =(4)/(5) and x is acute, find the value of tan2x .

If 4sin^(2)x^(@)-3=0" and "x^(@) is an acute angle, find : (i) sinx^(@) " (ii) "x^(@)

If 4sin^(2)x^(@)-3=0" and "x^(@) is an acute angle, find : (i) sinx^(@) " (ii) "x^(@)