18/97 to the nearest hundreth is 0.18
I don’t know , why don’t you tell me why they were selected
First we will convert those radian angles to degrees, since my mind works better with degrees. Let's work one at a time. First,

. If we start at the positive x-axis and measure out 315 we end up in the 4th quadrant with a reference angle of 45 with the positive x-axis. The side across from the reference angle is -1, the side adjacent to the angle is 1, and the hypotenuse is sqrt2. The cotangent of this angle, then is 1/-1 which is -1. As for the second one, converting radians to degrees gives us that

. Sweeping out that angle has us going around the origin more than once and ending up in the first quadrant with a reference angle of 30° with the positive x-axis. The side across from the angle is 1, the side adjacent to the angle is √3, and the hypotenuse is 2. Therefore, the secant of that angle is 2/√3.
Answer:
Yes, the function is a kernel
Step-by-step explanation:
Given
Document x an z
Function definition! k(x:z)
We want to show that the above is a kernel.
To do this, we'll explicitly construct feature vectors φ(x) and φ(z)
This gives;
K(x,z) =φ(x)·φ(z).
Given than any document; say x and z
A vocabulary V can be constructed.
Vocabulary V must have a finite size of words in the document set..
The feature mapping is constructed as φ(x) for x by the following:
For the kth word wk in V, if wk appears in document x, assign φ(x) k(the kth element ofφ(x)) to be 1; else φ(x)k to 0.
Then the number of unique words common in x and z is φ(x)·φ(z), giving us the kernel
.