Answer:
Step-by-step explanation:
(x+3)(x-3)
x squared and -9 are both square numbers.
the square root of x^2 is x
the square root of -9 is 3. so you just need to write (x+3)(x-3)
you can check by expanding the brackets and the middle x terms should cancel out
Answer:
4. $130.50
Step-by-step explanation:
Sorry, but I only know for no.4 which is $130.50.
Explanation: 18 hours is 20 percent more than 15 hours.
So all we have to do is multiply 1.2 to 108.75, since multiplying 1.2 is the equivalent to 20 percent.
Which then is why I get the answer of $130.50.
If that helped please hit Thank button!
Answer:
The answer is below
Step-by-step explanation:
Show that f(x) f(y) = f(x+y)
From trigonometric:
sin(x + y) = sinxcosy + cosxsiny
sin(x - y) = sinxcosy - cosxsiny
cos(x + y) = cosxcosy - sinxsiny
cos(x - y) = cosxcosy + sinxsiny
![f(x)=\left[\begin{array}{ccc}cosx&-sinx&0\\sinx&cosx&0\\0&0&1\end{array}\right] ,f(y)=\left[\begin{array}{ccc}cosy&-siny&0\\siny&cosy&0\\0&0&1\end{array}\right] \\\\\\f(x)f(y)=\left[\begin{array}{ccc}cosxcosy-sinxsiny&-cosxsiny-sinxcosy&0\\sinxcosy+cosxsiny&-sinxsiny+cosxcosy&0\\0&0&1\end{array}\right] \\\\\\f(x)f(y)=\left[\begin{array}{ccc}cos(x+y)&-sin(x+y)&0\\sin(x+y)&cos(x+y)&0\\0&0&1\end{array}\right] \\\\\\](https://tex.z-dn.net/?f=f%28x%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosx%26-sinx%260%5C%5Csinx%26cosx%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%2Cf%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosy%26-siny%260%5C%5Csiny%26cosy%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5Cf%28x%29f%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosxcosy-sinxsiny%26-cosxsiny-sinxcosy%260%5C%5Csinxcosy%2Bcosxsiny%26-sinxsiny%2Bcosxcosy%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5Cf%28x%29f%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcos%28x%2By%29%26-sin%28x%2By%29%260%5C%5Csin%28x%2By%29%26cos%28x%2By%29%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5C)
![f(x+y)=\left[\begin{array}{ccc}cos(x+y)&-sin(x+y)&0\\sin(x+y)&cos(x+y)&0\\0&0&1\end{array}\right] \\\\\\Therefore\ f(x)f(y)=f(x+y)](https://tex.z-dn.net/?f=f%28x%2By%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcos%28x%2By%29%26-sin%28x%2By%29%260%5C%5Csin%28x%2By%29%26cos%28x%2By%29%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5CTherefore%5C%20f%28x%29f%28y%29%3Df%28x%2By%29)
Answer:
1+.7= 1.7
Step-by-step explanation:
