Hi there!
We are given:
cos(7x)cos(4x) = -1 - sin(7x)sin(4x)
Begin by moving all terms with variables to one side:
cos(7x)cos(4x) + sin(7x)sin(4x) = -1
The corresponding trig identity is cos(A - B). Thus:
cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1
cos(3x) = -1
cos = -1 at π, so:
3x = π
x = π/3
We can also find another solution. Let 3π = -1:
3x = 3π
x = π
Thus, solutions on [0, 2π) are π/3 and π.
Answer:
D. 2x^2-7x.
Step-by-step explanation:
Lets write it out to make it easy to work with.
-x(-2x+7)
Multiply the -x out
2x^2-7x.
The answer is D
Lets say, for ease, that the vat can hold a total of 70 gallons (or whatever you would like to use.) Use whatever number you want, I just picked this because it gives us a lot of clean numbers.
Now, if the inlet can fill it in 7 hours, that means that it is adding 10 gallons per hour. (70 gal/7 hours = 10 gal/hr)
For the outlet, use the same process, and you find that it drains the vat at 7 gallons per hour.
So, if you subtract the outlet from the inlet, you get 10 - 7 = 3 gallons per hour added.
Now just divide the size of the vat by that number, and you find your answer.
70 gallons / 3 gallons per hour = 23 1/3 hours.
Answer:
Step-by-step explanation:
6^3 is the error, 6^3 is 216.
the correct volume is 904.32
Answer:
Step-by-step explanation:
Given
Required
Determine the difference
Represent this with d.
d is calculated using
The equation becomes
