Answer:
x cubed minus y cubed is equal to 504
Step-by-step explanation:
First we need to know what the values of x and y are. We can do this pretty easily, by just solving both equations for x, and equating them to each other:
With the first:
x + y = 10
x = 10 - y
And with the other
x - y = 6
x = 6 + y
Now that we have two definitions of x, we can say that the expressions are equal, and solve for y:
10 - y = 6 + y
10 - 6 = y + y
4 = 2y
y = 2
And now that we know what y is, we can find x:
x = 10 - y
x = 10 - 2
x = 8
So x is equal to eight. We can check our answer by plugging x into the other equation and seeing if we get the same value for y:
x - y = 6
8 - y = 6
-y = 6 - 8
-y = -2
y = 2
So we know we solved that correctly.
Now if we cube each number, eight cubed is equal to 512, and 2 cubed is equal to 8. If we subtract the latter from the former we get 504.
so x cubed minus y cubed is equal to 504
![\bf \stackrel{f(x)}{0}=-4cos\left(x-\frac{\pi }{2} \right)\implies 0=cos\left(x-\frac{\pi }{2} \right) \\\\\\ cos^{-1}(0)=cos^{-1}\left[ cos\left(x-\frac{\pi }{2} \right) \right]\implies cos^{-1}(0)=x-\cfrac{\pi }{2} \\\\\\ x-\cfrac{\pi }{2}= \begin{cases} \frac{\pi }{2}\\\\ \frac{3\pi }{2} \end{cases}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7Bf%28x%29%7D%7B0%7D%3D-4cos%5Cleft%28x-%5Cfrac%7B%5Cpi%20%7D%7B2%7D%20%20%5Cright%29%5Cimplies%200%3Dcos%5Cleft%28x-%5Cfrac%7B%5Cpi%20%7D%7B2%7D%20%20%5Cright%29%0A%5C%5C%5C%5C%5C%5C%0Acos%5E%7B-1%7D%280%29%3Dcos%5E%7B-1%7D%5Cleft%5B%20cos%5Cleft%28x-%5Cfrac%7B%5Cpi%20%7D%7B2%7D%20%20%5Cright%29%20%5Cright%5D%5Cimplies%20cos%5E%7B-1%7D%280%29%3Dx-%5Ccfrac%7B%5Cpi%20%7D%7B2%7D%0A%5C%5C%5C%5C%5C%5C%0Ax-%5Ccfrac%7B%5Cpi%20%7D%7B2%7D%3D%0A%5Cbegin%7Bcases%7D%0A%5Cfrac%7B%5Cpi%20%7D%7B2%7D%5C%5C%5C%5C%0A%5Cfrac%7B3%5Cpi%20%7D%7B2%7D%0A%5Cend%7Bcases%7D)
