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Convert the sums or differences into pro...

Convert the sums or differences into products:
`sin 37 ^(@) + sin 21 ^(@)`

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To convert the sum of sines into a product, we can use the sine addition formula. Here’s the step-by-step solution: ### Step 1: Identify the angles We have the expression: \[ \sin 37^\circ + \sin 21^\circ \] ### Step 2: Use the sine addition formula The formula for the sum of two sine functions is: \[ \sin C + \sin D = 2 \sin\left(\frac{C + D}{2}\right) \cos\left(\frac{C - D}{2}\right) \] In our case, \(C = 37^\circ\) and \(D = 21^\circ\). ### Step 3: Calculate \(C + D\) and \(C - D\) Now, we calculate: \[ C + D = 37^\circ + 21^\circ = 58^\circ \] \[ C - D = 37^\circ - 21^\circ = 16^\circ \] ### Step 4: Substitute into the formula Now we substitute these values into the sine addition formula: \[ \sin 37^\circ + \sin 21^\circ = 2 \sin\left(\frac{58^\circ}{2}\right) \cos\left(\frac{16^\circ}{2}\right) \] ### Step 5: Simplify the expression Calculating the halves: \[ \frac{58^\circ}{2} = 29^\circ \] \[ \frac{16^\circ}{2} = 8^\circ \] So we can rewrite the expression as: \[ \sin 37^\circ + \sin 21^\circ = 2 \sin(29^\circ) \cos(8^\circ) \] ### Final Answer Thus, the sum of \(\sin 37^\circ + \sin 21^\circ\) can be expressed as: \[ \sin 37^\circ + \sin 21^\circ = 2 \sin(29^\circ) \cos(8^\circ) \] ---
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ICSE-COMPOUND AND MULTIPLE ANGLES -EXERCISE 5 (B)
  1. Convert the products into sum or difference. If angles are given in de...

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  2. Convert the sums or differences into products: sin 12 A + sin 4 A

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  3. Convert the sums or differences into products: sin 37 ^(@) + sin 21 ...

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  4. Convert the sums or differences into products: sin 12 A - sin 4 A

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  5. Convert the sums or differences into products: cos 79^(@) + cos 11 ^...

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  6. Convert the sums or differences into products: cos 12 alpha + cos 8 ...

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  7. Convert the sums or differences into products: cos 25 ^(@) - cos 37^...

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  8. Convert the sums or differences into products: sin 61^(@) - cos 39^(...

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  9. Convert the sums or differences into products: sin 4x + cos 2x

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  10. Prove that: (sin A+sin B)/(cos A+cos B)=tan((A+B)/2)

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  11. (sin 75^(@) - sin 15 ^(@))/( cos 75^(@) + cos 15 ^(@)) = (1)/(sqrt3)

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  12. (sin 7x + sin 3x )/(cos 7x + cos 3x ) = tan 5x.

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  13. (cos 2B - cos 2 A)/( sin 2 A + sin 2 B) = tan (A -B).

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  14. (sin (4A - 2B) + sin (4B - 2 A))/( cos (4 A - 2 B) + cos (4B - 2 A))= ...

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  15. (cos alpha + 2 cos 3 alpha + cos 5 alpha )/(cos 3 alpha + 2 cos 5 alph...

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  16. ( sin A + sin 3A + sin 5A + sin 7A)/(cos A + cos 3 A + cos 5 A + cos 7...

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  17. cos 20^(@) + cos 100^(@) + cos 140^(@) = 0

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  18. Prove that :sin 10^(@) + sin 20^(@) + sin 40^(@) + sin 50^(@) = sin 70...

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  19. Prove that cos 15 ^(@) - sin 15^(@) = (1)/(sqrt2)

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  20. Prove that sin 36 ^(@) + cos 36 ^(@) = sqrt2 cos 9^(@).

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