

follows from the fact that the cosine function is

-periodic, which means

. Roughly speaking, this is the same as saying that a point on a circle is the same as the point you get by completing a full revolution around the circle (i.e. add

to the original point's angle with respect to the horizontal axis).
If you make another complete revolution (so we're effectively adding

) we get the same result:

. This is true for any number of complete revolutions, so that this pattern holds for any even multiple of

added to the argument. Therefore

for any integer

.
Next, because

, it follows that

is also true for any integer

. So we have

The rest follows from considering either case and solving for

.
Add 5 to both sides. Then 8x > -6, and x > -3/4 (answer)
Answer:
y = -6 + 1.2*x is the answer I would use, but see the note below.
Step-by-step explanation:
Let x = the number of minutes.
Let y = the temperature at any given time.
y = -6 + 1.2*x
This is the equation that you would use if you were calculating y with a calculator. If you are in a chemistry class it should be written as
y = - 6°C + 1.2°x/ min
Answer:
Percy used 77 liters to wash
Step-by-step explanation:
This question can be solved using a rule of three.
Each minute of washing costs 7 liters.
She washed for 11 minutes.
So
1 minute - 7 liters
11 minutes - x liters
x = 7*11 = 77
Percy used 77 liters to wash
Answer:
y=1/x-1/5
Step-by-step explanation:
tell me if u have more questions
y=-x+5
is the line so to make it perpendicular
y=1/x-1/5 i gtg