Question

evaluate Sin² 42 - sin? sin² 12​

Answer 1

Ans= Sin (42'+ 12'). sin(42'-12').

Step-by-step explanation:

sin 54'. sin 30 SinA+b) - sinA-b= sin2a- sin2b sin (90'-36')×1/2. cos36' × 1/2. √5+1/4×1/2. =√5+1/8 Answer✓✓