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) = 
7/4
4 goes into 7 one time.
3 left over.
1 3/4
-1,+2,+4,+6,+8
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Answer:
3m+m^2
Step-by-step explanation: