<span>Tan(x) = sin(x) / cos(x). Therefore, tan(x) pi/2 = 1/0, which doesn't exist. Imagine that, instead of 0, it's a number incredibly close to 0. The smaller the number in the denominator, the bigger the outcome. Therefore, we can think of 1/0 as infinity, or approaching infinity as one gets closer to 1/0. This is the same result approaching from the negative side, only it's negative infinity. If x=0, it's 0/1 instead (sin 0=0, cos 0=1). Anything divided by 1 is itself, so as x approaches 0, so does f(x).</span>
The event that either M1 or M2 fails has probability
![P(M_1\text{ fails or }M_2\text{ fails})=P(M_1\text{ fails})+P(M_2\text{ fails})-P(M_1\text{ and }M_2\text{ both fail})](https://tex.z-dn.net/?f=P%28M_1%5Ctext%7B%20fails%20or%20%7DM_2%5Ctext%7B%20fails%7D%29%3DP%28M_1%5Ctext%7B%20fails%7D%29%2BP%28M_2%5Ctext%7B%20fails%7D%29-P%28M_1%5Ctext%7B%20and%20%7DM_2%5Ctext%7B%20both%20fail%7D%29)
by the addition rule. Failure events are independent, so
![P(M_1\text{ and }M_2\text{ both fail})=P(M_1\text{ fails})P(M_2\text{ fails})](https://tex.z-dn.net/?f=P%28M_1%5Ctext%7B%20and%20%7DM_2%5Ctext%7B%20both%20fail%7D%29%3DP%28M_1%5Ctext%7B%20fails%7D%29P%28M_2%5Ctext%7B%20fails%7D%29)
so that
![P(M_1\text{ fails or }M_2\text{ fails})=p_1+p_2-p_1p_2](https://tex.z-dn.net/?f=P%28M_1%5Ctext%7B%20fails%20or%20%7DM_2%5Ctext%7B%20fails%7D%29%3Dp_1%2Bp_2-p_1p_2)
Denote this probability by
. Then
follows a geometric distribution with this parameter
and has density
![P(X=x)=\begin{cases}(1-p)^{x-1}p&\text{for }x\ge1\\0&\text{otherwise}\end{cases}](https://tex.z-dn.net/?f=P%28X%3Dx%29%3D%5Cbegin%7Bcases%7D%281-p%29%5E%7Bx-1%7Dp%26%5Ctext%7Bfor%20%7Dx%5Cge1%5C%5C0%26%5Ctext%7Botherwise%7D%5Cend%7Bcases%7D)
The expectation is
.
Answer:
A, B, D, F
Step-by-step explanation:
The proof is to show your work
An easier way to do this is to make the fractions improper fractions.
3 1/6 can be rewritten as 19/6. 1 4/6 can be rewritten as 10/6. (Multiply the denominator by the number at its side, and add it to the numerator).
2 3/6 is 15/6.
Subtract 10/6 from 19/6.
19/6-10/6=9/6.
9/6 is not 15/6, therefore she did not use 2 3/6 yards of fabric.