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

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

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To solve the problem, we need to find the values of angles A and B given the equations: 1. \( 2 \cos(A + B) = 1 \) 2. \( 2 \sin(A - B) = 1 \) Let's solve this step by step. ### Step 1: Simplify the equations From the first equation: \[ 2 \cos(A + B) = 1 \] Dividing both sides by 2 gives: \[ \cos(A + B) = \frac{1}{2} \] From the second equation: \[ 2 \sin(A - B) = 1 \] Dividing both sides by 2 gives: \[ \sin(A - B) = \frac{1}{2} \] ### Step 2: Identify standard angles We know that: \[ \cos(60^\circ) = \frac{1}{2} \] Thus, we can write: \[ A + B = 60^\circ \quad \text{(Equation 1)} \] Also, we know that: \[ \sin(30^\circ) = \frac{1}{2} \] Thus, we can write: \[ A - B = 30^\circ \quad \text{(Equation 2)} \] ### Step 3: Solve the system of equations Now we have a system of two equations: 1. \( A + B = 60^\circ \) 2. \( A - B = 30^\circ \) We can solve these equations by adding them together: \[ (A + B) + (A - B) = 60^\circ + 30^\circ \] This simplifies to: \[ 2A = 90^\circ \] Dividing both sides by 2 gives: \[ A = 45^\circ \] ### Step 4: Substitute to find B Now we can substitute \( A = 45^\circ \) back into Equation 1 to find B: \[ 45^\circ + B = 60^\circ \] Subtracting \( 45^\circ \) from both sides gives: \[ B = 60^\circ - 45^\circ = 15^\circ \] ### Final Answer Thus, the values of A and B are: \[ A = 45^\circ, \quad B = 15^\circ \] ---
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ICSE-TRIGONOMETRICAL RATIOS OF STANDARD ANGLES-EXERCISE 23(C)
  1. In DeltaABC, angleB=90^@), AB=y" units", BC=sqrt(3) " units", AC = 2 u...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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  16. Calculate the value of A, if : (cosec2A-2)(cot3A-1)=0

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  17. If 2sinx^(@)-1=0 and x^(@) is an acute angle, find: (i) bsinx^(@)" ...

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  18. If 4cos^(2)x^(@)-1=0 and 0 le x^(@) le 90^(@), find : x^(@)

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  19. If 4cos^(2)x(@)-1=0 and 0 le x^(@) le 90^(@), find : sin^(2)x^(@)+co...

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  20. If 4cos^(2)x(@)-1=0 and 0 le x^(@) le 90^(@), find : 1/(cos^(2)x^(@)...

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