Tan (∠R) = 21/20
∠R = tan¯¹ (21/20) ~ 46.4°
Answer: 2.308 .
Step-by-step explanation:
Let X denotes the number of earthquakes in SanFernando valley region of Los Angeles in 1994.
Given: 
Probability is 0.87 that there will be at least 15 earthquakes .
i.e. 
![\Rightarrow\ P(\dfrac{X-\mu}{\sigma}\geq\dfrac{15-17.6}{\sigma})=0.87\\\\ \Rightarrow\ P(Z\geq\dfrac{-2.6}{\sigma})=0.87\ \ \ [Z=\dfrac{X-\mu}{\sigma}]](https://tex.z-dn.net/?f=%5CRightarrow%5C%20P%28%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5Cgeq%5Cdfrac%7B15-17.6%7D%7B%5Csigma%7D%29%3D0.87%5C%5C%5C%5C%20%20%5CRightarrow%5C%20P%28Z%5Cgeq%5Cdfrac%7B-2.6%7D%7B%5Csigma%7D%29%3D0.87%5C%20%5C%20%5C%20%5BZ%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5D)
Z-value corresponding to p-value 0.87 is -1.1263 .
So, 
Hence, the required standard deviation = 2.308 .
Acute-The angle is less than 90 degrees
Equilateral-All sides are equal in length
Isosceles-Two of the sides are equal in length
Scalene-None of the sides are equal in length
Right-The angle is 90 degrees
Obtuse-The angle is greater than 90 degrees
We can see that none of the sides are the same length, so we know that it must be scalene. We can also see that every angle is less than 90 degrees, so we know that is must be acute.
The triangle is scalene and acute.
Hope this helps!!
Answer: y² = 8x
Step-by-step explanation:
The set of points which are equidistant from one point and from a line is a parabola.
In this particular case we have directrix line × = -2 so that means focus must be on the x-axis and with coordenates f (2,0) and p = 2 (the distance between the vertex and the focus with that information we can get the equation
vertex ( 0, 0) p = 2 the parabola open to the left so is of the form
y² =- 4*p*× ⇒ y² = 8x
