Answer:
Well, I don't know how to graph it for you, but the slope is -2/3 and the point is (-9, 5). So, when you graph it, from the point (-9, 5), you can go 3 units to the right and 2 units down.
Question 1132387: How many liters of a 10% solution should be mixed with 60L of 25% solution to get 15% solution? = one click in Excel = 120. ANSWER. 120 liters of the 10% solution.
The question is:
Check whether the function:
y = [cos(2x)]/x
is a solution of
xy' + y = -2sin(2x)
with the initial condition y(π/4) = 0
Answer:
To check if the function y = [cos(2x)]/x is a solution of the differential equation xy' + y = -2sin(2x), we need to substitute the value of y and the value of the derivative of y on the left hand side of the differential equation and see if we obtain the right hand side of the equation.
Let us do that.
y = [cos(2x)]/x
y' = (-1/x²) [cos(2x)] - (2/x) [sin(2x)]
Now,
xy' + y = x{(-1/x²) [cos(2x)] - (2/x) [sin(2x)]} + ([cos(2x)]/x
= (-1/x)cos(2x) - 2sin(2x) + (1/x)cos(2x)
= -2sin(2x)
Which is the right hand side of the differential equation.
Hence, y is a solution to the differential equation.
