Home
Class 12
MATHS
If f(theta) = (1- sin 2theta + cos 2thet...

If `f(theta) = (1- sin 2theta + cos 2theta)/(2sin 2theta)` then value of` f(11^o). f(34^o)` is

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to evaluate the function \( f(\theta) = \frac{1 - \sin 2\theta + \cos 2\theta}{2 \sin 2\theta} \) for \( \theta = 11^\circ \) and \( \theta = 34^\circ \), and then find the product \( f(11^\circ) \cdot f(34^\circ) \). ### Step-by-Step Solution: 1. **Rewrite the Function**: We start with the function: \[ f(\theta) = \frac{1 - \sin 2\theta + \cos 2\theta}{2 \sin 2\theta} \] 2. **Use Trigonometric Identities**: Recall that: \[ \sin 2\theta = 2 \sin \theta \cos \theta \] and \[ \cos 2\theta = \cos^2 \theta - \sin^2 \theta = 2\cos^2 \theta - 1 \] Thus, we can rewrite: \[ f(\theta) = \frac{1 - 2 \sin \theta \cos \theta + (2 \cos^2 \theta - 1)}{2 \cdot 2 \sin \theta \cos \theta} \] Simplifying the numerator: \[ f(\theta) = \frac{2 \cos^2 \theta - 2 \sin \theta \cos \theta}{4 \sin \theta \cos \theta} \] Factoring out the common terms: \[ f(\theta) = \frac{2 \cos \theta (\cos \theta - \sin \theta)}{4 \sin \theta \cos \theta} = \frac{\cos \theta - \sin \theta}{2 \sin \theta} \] 3. **Evaluate \( f(11^\circ) \)**: \[ f(11^\circ) = \frac{\cos 11^\circ - \sin 11^\circ}{2 \sin 11^\circ} \] 4. **Evaluate \( f(34^\circ) \)**: \[ f(34^\circ) = \frac{\cos 34^\circ - \sin 34^\circ}{2 \sin 34^\circ} \] 5. **Find the Product \( f(11^\circ) \cdot f(34^\circ) \)**: \[ f(11^\circ) \cdot f(34^\circ = \left( \frac{\cos 11^\circ - \sin 11^\circ}{2 \sin 11^\circ} \right) \cdot \left( \frac{\cos 34^\circ - \sin 34^\circ}{2 \sin 34^\circ} \right) \] This simplifies to: \[ = \frac{(\cos 11^\circ - \sin 11^\circ)(\cos 34^\circ - \sin 34^\circ)}{4 \sin 11^\circ \sin 34^\circ} \] 6. **Use the Angle Difference Identity**: We can use the identity for \( \tan(45^\circ - x) \): \[ \tan(45^\circ - 11^\circ) = \frac{1 - \tan 11^\circ}{1 + \tan 11^\circ} \] Thus, \( \tan(34^\circ) = \tan(45^\circ - 11^\circ) \). 7. **Final Calculation**: After substituting and simplifying, we find that: \[ f(11^\circ) \cdot f(34^\circ) = \frac{1}{2} \] ### Conclusion: The value of \( f(11^\circ) \cdot f(34^\circ) \) is \( \frac{1}{2} \).

To solve the problem, we need to evaluate the function \( f(\theta) = \frac{1 - \sin 2\theta + \cos 2\theta}{2 \sin 2\theta} \) for \( \theta = 11^\circ \) and \( \theta = 34^\circ \), and then find the product \( f(11^\circ) \cdot f(34^\circ) \). ### Step-by-Step Solution: 1. **Rewrite the Function**: We start with the function: \[ f(\theta) = \frac{1 - \sin 2\theta + \cos 2\theta}{2 \sin 2\theta} ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • TRIGONOMETRIC RATIOS AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Single correct Answer Type (Archives) JEE Main|5 Videos
  • TRIGONOMETRIC RATIOS AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Single correct Answer Type (Archives) JEE Advanced|1 Videos
  • TRIGONOMETRIC RATIOS AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Exercise (Linked Comprehension Type)|20 Videos
  • TRIGONOMETRIC FUNCTIONS

    CENGAGE ENGLISH|Exercise SINGLE CORRECT ANSWER TYPE|38 Videos
  • TRIGONOMETRIC RATIOS FOR COMPOUND, MULTIPLE, SUB-MULTIPLE ANGLES, AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Multiple Correct Answers Type|6 Videos

Similar Questions

Explore conceptually related problems

If f(theta)=(1-sin2theta+cos2theta)/(2cos2theta) , then value of 8f(11^0)*f(34^0) is ____

(1+sin 2theta+cos 2theta)/(1+sin2 theta-cos 2 theta) =

Knowledge Check

  • sin^(3)theta + sin theta - sin theta cos^(2)theta =

    A
    0
    B
    `sin theta`
    C
    `sin 2 theta`
    D
    `2sin^(3)theta`
  • Similar Questions

    Explore conceptually related problems

    If f (theta) = |sin theta| + |cos theta|, theta in R , then

    (1+sin2theta+cos2theta)/(1+sin2theta-cos2theta)=?

    Range of f(theta)=cos^2theta(cos^2theta+1)+2sin^2theta is

    Solve : 3-2 cos theta -4 sin theta - cos 2theta+sin 2theta=0 .

    Prove : (cos theta)/(1+sin theta) + (cos theta)/(1-sin theta)= 2 sec theta

    (sin theta + sin 2 theta)/( 1 + cos theta + cos 2 theta) = tan theta.

    Prove : (1+sin2theta-cos2theta)/(1+sin2theta+cos2theta)=tantheta