Answer:
1) -0.669
2) -0.669
3) 0.669
Step-by-step explanation:
Since we are subtracting or adding multipled of pi, we will either obtain 0.669 or -0.669 as our answer for each of the three different questions.
Cosine is the x-coordinate in our orderes pairs. If our point ends up on the right side of the y-axis, the cosine will be positive. If our point ends up on left side, it will be negative.
Choose a thetha (I'm going to choose it in degrees) in the first quadrant to help with a visual.
If theta=70:
1) then 180-70=110 which is in second quadrant, so our cosines will be opposite in value.
2) then 180+70=250 which is in third quadrant, so our cosines will be opposite in value.
3) then 4×180-70=720-70=650 =1(360)+290 which ends up in the 4th quadrant which means the consines will have the same value.
Answer:

Step-by-step explanation:
Here, the given expression is:

Now, by logarithm rules, we know
if 
, then x =
Comparing here, b = 10 and z = 2
⇒ y = 
or, 
He would have 21 before he bought the 10 stamp because 31-10=21
Answer:
The slope is 2/3 and the function is y=2/3x which is a direct variation function.
Step-by-step explanation:
To find the slope of a line between two points, we use the equation
m = (y2-y1)/ (x2-x1)
where (x1,y1) and (x2,y2) are the two points
m= (4-2)/(6-3)
= 2/3
The slope of the line is 2/3
The equation of the line is
y-y1 = m(x-x1)
y-2 = 2/3(x-3)
Distribute
y-2 = 2/3x -2
Add 2 to each side
y-2+2 = 2/3x -2+2
y = 2/3x
This is a direct variation function
Let x = -6
y = 2/3(-6)
y = -4
(-6,-4)