Question

sin35.sin55-cos35.cos55​

Answer 1

Answer:

The value of sin 35*sin 55 - cos 35*cos 55 has to be determined.

Here it is not necessary to know the values of the sine or cosine of 35 or 55.

Instead use the rule: sin a*sin b - cos a*cos b = -cos(a + b)

sin 35*sin 55 - cos 35*cos 55

=> -cos(35 + 55)

=> -cos 90

=> 0

Answer 2

Step-by-step explanation:

The value of sin 35*sin 55 - cos 35*cos 55 has to be determined.

Here it is not necessary to know the values of the sine or cosine of 35 or 55.

Instead use the rule: sin a*sin b - cos a*cos b = -cos(a + b)

sin 35*sin 55 - cos 35*cos 55

=> -cos(35 + 55)

=> -cos 90

=> 0