4. The reflecting dish of a parabolic microphone has a cross-section in the shape of a parabola.
The microphone itself is placed on the focus of the parabola. If the parabola is 40 inches wide
and 20 inches deep, how far from the vertex should the microphone be placed?
4 inches
5 inches
8 inches
10 inches

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.

answer: do we write it

step-by-step explanation:

11.2

step-by-step explanation:

when doing tangent the tangent of the angle is equal to the opposite side from the angle over the adjacent side to the angle.

tan43 = x / 12

move 12 over by multiplying each side by 12

12tan43 = x

x = about 11.2