<span>y = -5 cos x is a basic (simple) variation of the basic trig function y = cos x.
The given </span>y = -5 cos x could be re-written as <span>y = -5 cos 1x.
Compare this to the most general form: y = a cos bx.
Here we see that the coefficient b equals 1.
There is a rule for finding the period of such a function: Period = 2pi/b.
Since b = 1 here, the Period here is 2pi/1, or simply 2pi.
Please stop saying "I'm terrible with math." That does not help you at all. Say, instead, "With just a little help I could understand this just fine."</span>
11/42
The way I got it is because I took 1/6 minus 3/7 to get the answer of f=11/42
Step-by-step explanation:

First, convert the mixed number into an improper fraction.
To convert a mixed number into an improper fraction, find the product of the whole number and the denominator and then add the numerator.
Then the denominator will be the original denominator from the mixed number.

=

Now the fraction

is being raised to the third power negative.
When an exponent is negative, it means to take the reciprocal of the number then raise it to the power of the absolute value of the exponent.
In a mathematical expression:

So, first take the reciprocal of

which is 3.
Then raise 3 to the absolute value of the exponent. The exponent is -3.
The absolute value of -3 is 3.
3^3 = 3 * 3 * 3 = 27
So, the answer is 27.