Question

lf sin (a+b) = sinA cosB +cosA sinB find sim 75°.hindi m

Answer 1

we have ,
sin(a+b) = sinA cos B +cosA sinB
then
sin( 30+45) = sin 30 cos 45 + cos 30 sin 45
= 1/2 × 1/√2 + 3/√2 × 1/√2
= 1/2√2 + 3 /2
= ( 1+3√2) / 2√2




hope it helps