Question

sin 140° cos 20°- cos 140° sin 20°

1) 1/2

2) 1/√2

3) √3/2

4) 1




WRONG ANSWER WILL BE REPORTED
CORRECT ANSWER WILL BE MARKED AS BRAINLIEST



ANSWER STEP BY STEP​

Answer 1

Solution :-

→ sin 140° cos 20° - cos 140° sin 20°

→ sin ( 140° - 20° )

→ sin 120°

→ √3/2

Identity Used :-

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

Answer 2

Answer:

Cos A. Cos B + Sin A . Sin B

Step-by-step explanation:

Cos 140° . Cos 20° + Sin 140°. Sin 20°

Sin ( A - B )

Sin ( 140° - 20°)

Sin (120°)

✓3/2