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) =
1813 x
= 326.34
18% of 1813 people is 326.34 people
333 is a reasonable estimate.
..... 40.5 ...............
Answer:
$420
Step-by-step explanation:
To work this out you would need to find the 25% decrease of 560. To do this you would first divide 25 by 100, which gives you 0.25. Then you would minus 0.25 from 1, which gives you 0.75. This is because when finding percentage decreases you would first have to convert it into a decimal. Then you would have to minus it from 1 , to make sure that it will be a 25% decrease not a 75% decrease. Then you would multiply 560 by 0.75, which gives you 420.
1) Divide 25 by 100.
2) Minus 0.25 from 1.
3) Multiply 560 by 0.75.
Alaina has $28 in her account and wants to buy shoes worth $45
So $28-$45=$-17
Her account status will be $ - 17
Hope this helps
