Answer: 
<u>Step-by-step explanation:</u>
Given: cos x =
, x is in Quadrant 4
Use Pythagorean Theorem to find sin x:
8² + y² = 17²
y² = 17² - 8²
y² = 289 - 64
y² = 225
y = 15
→ sin x = 
Use the double angle formula to find cos (2x):

Answer:
y = 2x - 3
Step-by-step explanation:
We are asked to find the equation of a straight line
Step 1: find the slope
( 2 , 1) ( 5 , 7)
x_1 = 2
y_1 = 1
x_2 = 5
y_2 = 7
Insert the values into the equation
m = (y_2 - y_1 )/ (x_2 - x _1)
m = (7 - 1 )/ (5 - 2)
m = 6/3
= 2
Step 2: substitute m into the equation
y = mx + c
y = 2x + c
Step 3 : sub any of the two points given into the equation
Let's use ( 2, 1)
x = 2
y = 1
y = 2x + c.
1 = 2(2) + c
1 = 4 + c
c = 1 - 4
c = -3
Step 4: sub c into the equation
y = 2x + c
y = 2x - 3
Answer:
Option A
Step-by-step explanation:
We can try to factorize all the options one by one.
For A:

We can see that the quadratic expression cannot be solved by factorization as the factors at the end of factorization are not equal in both brackets. So Option A is the correct answer for the given question.
Moreover we can also note that all the other quadratic expressions can be factorized ..
Center: 0,0
vertex: 5,0
vertex2 (-5,0)
Rancho middle school has an average of 23 3/8 students per teacher.write this mixed number as a decimal.
Answer:

Step-by-step explanation:
Given:
The given mixed number is 
We need to write the given mixed number as a decimal.
So, we find the decimal number by separating the parts.

The value of 


Therefore, the decimal number of given mixed number is 