Answer:
cos(a + b) = 
Step-by-step explanation:
cos(a + b) = cos(a).cos(b) - sin(a).sin(b) [Identity]
cos(a) = 
cos(b) = 
Since, terminal side of angle 'a' lies in quadrant 3, sine of angle 'a' will be negative.
sin(a) =
[Since, sin(a) =
]
= 
= 
Similarly, terminal side of angle 'b' lies in quadrant 2, sine of angle 'b' will be negative.
sin(b) =
= 
= 
By substituting these values in the identity,
cos(a + b) = 
= 
= 
= 
Therefore, cos(a + b) = 
There is a 6% decrease as 639.20 divided 680 is 0.94. Meaning 6% decrease.
Answer:
-14n^4 + 7n^2 + 8n + 7
Step-by-step explanation:
( 8n - 3n^4 + 10n^2 ) - ( 3n^2 + 11n^4 - 7)
8n - 3n^4 + 10n^2 - 3n^2 - 11n^4 + 7
- 14n^4 + 7n^2 + 8n + 7
Answer:
The slower train's speed is 359.8 mph
x+5.2mph=359.8mph+5.2mph=365 mph ANSWER 2: The faster trains speed is 365 mph.
CHECK:
359.8 mph + 365 mph = 724.8 mph
724.8 mph = 724.8 mph
Step-by-step explanation: