Question

15 If A = 60° and B = 30°, verify that:
(i) sin (A-B) = sin A cos B - cos Asin B​

Answer 1

Answer:

sin (A-B) = sin A cos B - cos Asin B

given A = 60° and B = 30°,

sin (60-30) = sin 60cos 30 - cos 60sin 30

sin30= √3/2 × √3/2 - 1/2 × 1/2

sin30= 3/4 - 1/2 = 1/4

1/2 = 1/4

here LHS= not RHS

Answer 2

Step-by-step explanation:

sin(A-B)=Sin (60-30)

=Sin 30 =1/2

SinA CosB - cosA SinB

=Sin60 cos30 - cos60 sin30

=√3/2*√3/2 - 1/2*1/2

=3/4 - 1/4 =1/2

hence proved, they are equal