Answer:

Step-by-step explanation:
Given


Required

In trigonometry:

We need to solve for cosA, sinA and sinB
Given that:
and the tangent of an angle is a ratio of the opposite side (x) to the adjacent side (y),
So, we have:
and 
For this angle A, we need t calculate its hypotenuse (z).
Using Pythagoras,





From here, we can calculate sin and cos A
and 




To angle B.
Give that
and the cosine of an angle is a ratio of the adjacent side (a) to the hypotenuse side (c),
So, we have:
and 
For this angle B, we need to calculate its opposite (b).
Using Pythagoras,



Collect like terms




From here, we can calculate sin B



Recall that:
and





Step-by-step explanation:
Let the number of books of Physics be x . Then , No. of chemistry books =3.5x
Now , according to question :
x+3.5x=90
Or , 4.5x=90
Or , x=90/4.5
Or , x=20
Now ,
3.5x= 3.5×20
= 70
Therefore , there were 70 chemistry books and 20 physics books in that question bank.
Answer:
-5
Step-by-step explanation:
-4+(-3)-(-2)
-4-3+2
-7+2
-5
Answer:
B and C
Step-by-step explanation:
Uses my calculator and put the table in for worker be and thats how i found the slope was 12.5 . then i used to to figure out that when the hour got to 10 worker B starts making more money.
<span>D-21.4=87.9 \ solve for D
add 21.4 to both sides
</span><span>D - 21.4 +21.4 =87.9 + 21.4
simplify
D = 109.3</span>