We need to convert this equation to slope-intercept form first.
We can do that by solving for y.
x - 5y = 15
<em><u>Add 5y to both sides.</u></em>
x = 5y + 15
<em><u>Subtract 15 from both sides.</u></em>
x - 15 = 5y
<em><u>Divide both sides by 5.</u></em>
y = 1/5x - 3
We now know the slope is 1/5.
The slope of the line perpendicular to the line with a slope of 1/5 is -5.
The slope of a perpendicular line is the negative reciprocal of the original slope.
Using a graphing calculator, we know the y-intercept of the line that is perpendicular to the original line must have a y-intercept of -6 to run through the points (-2, 5).
The equation of the new line is y = -5x - 6.
Answer:
θ = π/3, 5π/3
Step-by-step explanation:
2 cos θ - 1 = 0
2 cos θ = 1
cos θ = 1/2
θ = π/3, 5π/3
Step-by-step explanation:

Answer:
And we can find this probability with the normal standard distirbution or excel and we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the lenghts of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with the normal standard distirbution or excel and we got: