Given sin(A+B)=SinA cosB +cosA sinB then find the value of sin 75°

1.	Given sin(A+B)=SinA cosB +cosA sinB then find the value of sin 75°
Answer» Let A=45°,B=30°(so that sum of A and B =75° and we can get Sin74°)(put the value of A and B in equation) - Sin75°=Sin45°Cos30° + Cos 45°Sin30°- Sin75° = 1/√2√3/2 + 1/√21/2- Sin75° = √3/2√2 + 1/2√2- Sin75° = (√3+1)/2√2Sin75° = (√6+√2)/4 sin ( A+ B) = sin75°Let A = 45° and B = 30°Thensin75° = sin45° cos30° + cos45° sin30°= 1/√2 * √3/2 + 1/√2 * 1/2= √3 / 2√2 + 1/2√2= √3 + 1/2√2You can rationalise the denominator.

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