This is not a random sample since she is outside of a pet store and the probability of people owning a dog coming out of that store is very very high. If she went around the neighborhood and knocked on people’s door and asked if they had a dog or not would be random sample.
Answer: x=−5 or x=5
Step-by-step explanation:
−3x4+27x2+1200=0
Step 1: Factor left side of equation.
−3(x2+16)(x+5)(x−5)=0
Step 2: Set factors equal to 0.
x2+16=0 or x+5=0 or x−5=0
x=−5 or x=5
Let AM be the distance between point A and the right wall and AN be the distance between A and the left wall.
Δ AMB is an isosceles right triangle and Δ ANC is half of an equilateral triangle.
Length of AM = 30 m. Length of AN = 1/2 · 80 = 40 m.
The distance between the walls is:
30 m + 40 m = 70 m.
You have to build the triangles.
They are such that:
h is the common height
x is the horizontal distance from the plane to one stone
Beta is the angle between x and the hypotenuse
Then in this triangle: tan(beta) = h / x ......(1)
1 - x is the horizontal distance from the plane to the other stone
alfa is the angle between 1 - x and h
Then, in this triangle: tan (alfa) = h / [1 -x ] ...... (2)
from (1) , x = h / tan(beta)
Substitute this value in (2)
tan(alfa) = h / { [ 1 - h / tan(beta)] } =>
{ [ 1 - h / tan(beta) ] } tan(alfa) = h
[tan(beta) - h] tan(alfa) = h*tan(beta)
tan(beta)tan(alfa) - htan(alfa) = htan(beta)
h [tan(alfa) + tan(beta) ] = tan(beta) tan (alfa)
h = tan(beta)*tan(alfa) / (t an(alfa) + tan(beta) )
