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If 3 sin theta + 5 cos theta = 5, then t...

If `3 sin theta + 5 cos theta = 5`, then the value of `5 sin theta - 3 cos theta` will be.

A

`(a) +3`

B

(b)`+5`

C

(c)`+2`

D

(d) `+1`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the value of \( 5 \sin \theta - 3 \cos \theta \) given that \( 3 \sin \theta + 5 \cos \theta = 5 \). ### Step-by-Step Solution: 1. **Identify the equations:** We have two expressions: - Equation 1: \( 3 \sin \theta + 5 \cos \theta = 5 \) - Equation 2: \( x = 5 \sin \theta - 3 \cos \theta \) (This is what we need to find.) 2. **Square both equations:** We will square both equations to help eliminate the sine and cosine terms later. - Squaring Equation 1: \[ (3 \sin \theta + 5 \cos \theta)^2 = 5^2 \] Expanding this gives: \[ 9 \sin^2 \theta + 30 \sin \theta \cos \theta + 25 \cos^2 \theta = 25 \] - Squaring Equation 2: \[ (5 \sin \theta - 3 \cos \theta)^2 = x^2 \] Expanding this gives: \[ 25 \sin^2 \theta - 30 \sin \theta \cos \theta + 9 \cos^2 \theta = x^2 \] 3. **Combine the squared equations:** Now we will add the two squared equations: \[ (9 \sin^2 \theta + 30 \sin \theta \cos \theta + 25 \cos^2 \theta) + (25 \sin^2 \theta - 30 \sin \theta \cos \theta + 9 \cos^2 \theta) = 25 + x^2 \] Simplifying the left side: \[ (9 + 25) \sin^2 \theta + (25 + 9) \cos^2 \theta + (30 - 30) \sin \theta \cos \theta = 25 + x^2 \] This simplifies to: \[ 34 \sin^2 \theta + 34 \cos^2 \theta = 25 + x^2 \] 4. **Use the Pythagorean identity:** We know that \( \sin^2 \theta + \cos^2 \theta = 1 \): \[ 34(1) = 25 + x^2 \] Thus: \[ 34 = 25 + x^2 \] 5. **Solve for \( x^2 \):** Rearranging gives: \[ x^2 = 34 - 25 \] Therefore: \[ x^2 = 9 \] 6. **Find the value of \( x \):** Taking the square root gives: \[ x = \pm 3 \] Hence, the value of \( 5 \sin \theta - 3 \cos \theta \) can be either \( 3 \) or \( -3 \). ### Conclusion: The value of \( 5 \sin \theta - 3 \cos \theta \) is \( \pm 3 \).

To solve the problem, we need to find the value of \( 5 \sin \theta - 3 \cos \theta \) given that \( 3 \sin \theta + 5 \cos \theta = 5 \). ### Step-by-Step Solution: 1. **Identify the equations:** We have two expressions: - Equation 1: \( 3 \sin \theta + 5 \cos \theta = 5 \) - Equation 2: \( x = 5 \sin \theta - 3 \cos \theta \) (This is what we need to find.) ...
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Knowledge Check

  • If 3 sin theta + 5 cos theta =5, then the value of (5 sin theta - 3 cos theta ) is

    A
    4
    B
    3
    C
    2
    D
    1
  • If 3 sin theta + 4 cos theta =5 , then value of sin theta is

    A
    `2/3`
    B
    `4/5`
    C
    `3/5`
    D
    `5/3`
  • If cot theta = 4, then the velue of (5 sin theta + 3 cos theta)/(5 sin theta - 3 cos theta )

    A
    `1/9`
    B
    `1/3`
    C
    `3`
    D
    9
  • Similar Questions

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    If 5 tan theta = 3, then what is the value of ((5 sin theta - 3 cos theta)/(4 sin theta + 3 cos theta)) ?

    If 3 sin theta + 4 cos theta = 5 , then 3 cos theta - 4 sin theta is equal to?