How to calculate the distance from parabolic focus to hyperbolic asymptote?

How to calculate the distance from parabolic focus to hyperbolic asymptote?

The distance between the point and the line is | ax + by + C | / root sign (a ^ 2 + B ^ 2)
The hyperbola C and the ellipse have the same focus when the square of 8 / x plus the square of 4 / y equals 1. The asymptote of C is x with the straight line y equal to 3 times the root sign
Solving the equation of hyperbola C
Ellipse a ^ 2 = 8 B ^ 2 = 4
c^2=a^2-b^2=4
So the hyperbolic focus coordinates are (- 2,0) and (2,0)
Because the line y is equal to three times the root, X is an asymptote of C
Then B / a = √ 3
B = √ 3A square
b^2=3a^2
Hyperbola a a ^ 2 + B ^ 2 = C ^ 2 = 4
a=1 b=√3
The hyperbolic equation is x ^ 2-y ^ 2 / 3 = 1
In the following functions, the minimum value of 2 is a, y = 2 / x + X / 2 B, y = radical (x2 + 2) + 1 / radical (x2 + 2) C, y = 8 ^ x + 8 ^ (- x) d, y = x ^ 2 + 8 / X (x > 1)
According to the mean inequality, B and C can only be determined to be greater than 2, and there is no minimum value
A and D are not suitable for mean inequality
But it can be judged that the minimum value of item a is not 2
The answer can only be d
All formulas of arithmetic sequence (literal, including first term, last term, number of terms, general term and summation)
① Sum = (first item + last item) × number of items △ 2
(2) number of items = (last first item) △ tolerance + 1
(3) first term = 2 and △ number of terms - last term
(4) last term = 2 and △ number of terms - first term
(converted to the first inference of more than 2 terms)
(5) last item = first item + (number of items - 1) × tolerance