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) = 
I'm pretty sure you're right. I got B to be the answer alsooo. Good job.
Have a good day! :D
X-y=-10
x=-10-y
7x+7y=-14
7(-10-y)+7y=-14
-70-7y+7y=-14
0y=56
y=0
x=-10-y
x=-10-0
x=-10
I’m not 100% sure if this is right, so I hope someone checks this over :)
Answer:
Step-by-step explanation:
Answer:
13 + 5 + 37
Step-by-step explanation: