Answer:
x = π/4 and 5π/4
Step-by-step explanation:
Given the expression;
2cos²x - 1 = 0
2cos²x = 0+1
2cos²x = 1
cos²x = 1/2
cos x = ±√1/2
cos x = ±0.7071
x = arccos(±0.7071)
x = ±45 degrees
Convert to radians
Sence 180° = π rad
45° = x
x = 45π/180
x = π/4
If x = -45°
Since cos is negative in the 3rd quadrant
x = 180 + 45
x = 225°
x = 225π/180
x = 45π/36
x = 5π/4
Answer:
y = -
x - 1
Step-by-step explanation:
Assuming you require the equation of the line
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Here m = -
, then
y = -
x + c ← is the partial equation
To find c substitute (12, - 4) into the partial equation
- 4 = - 3 + c ⇒ c = - 4 + 3 = - 1
y = -
x - 1 ← equation of line
Answer:

Step-by-step explanation:
-For a known standard deviation, the sample size for a desired margin of error is calculated using the formula:

Where:
is the standard deviation
is the desired margin of error.
We substitute our given values to calculate the sample size:

Hence, the smallest desired sample size is 23
Please give thanks and brainliest if correct!
The correct answer is B. -2x-6