Step-by-step explanation:
We know that tan=sin/cos, so tan(x+π/2)=

Then, we know that sin(u+v)=sin(u)cos(v)+cos(u)sin(v),
so our equation is then
Then, cos(u+v)=cos(u)cos(v)-sin(u)sin(v), so our expression is then

Answer:

point slope form....
y - (-7) = -1/2(x-4)
y + 7 = -x/2 + 2
2y + 14 = -x + 4
2y = -x -10
y = -1/2 x - 5
Step-by-step explanation:
Answer:
36
Step-by-step explanation:
40 * .10 = 4
40-4 = 36
Answer:
see explanation
Step-by-step explanation:
The equation of 2 quantities in direct proportion is
y = kx ← k is the constant of proportionality
1
y = - 4x ← in standard form
with k = - 4
2
= 2 ( multiply both sides by x )
y = 2x ← in standard form
with k = 2
3
= 3 ( multiply both sides by y )
x = 3y ( divide both sides by 3 )
x = y ← in standard form
with k = 
Answer:
Daniel (now) is 3 years old, (2 years ago) is 1 year old.
Kevin (now) is 6 years old, (2 years ago) is 4 years old.
Step-by-step explanation:
Now:
-Kevin: k = d + 3
-Daniel: d
2 years ago:
-Kevin: k - 2 = 4(d - 2)
-Daniel: d - 2
We have the equation:
(k - 2) + 2 = k
4(d - 2) + 2 = d + 3
4d - 8 + 2 = d + 3
3d - 6 = 3
3d = 9
d = 3
k = d + 3 = 3 + 3 = 6