Assume that an airplane is flying toward you at a constant height h = 1 mile and at a speed dxdt=−20 miles/hr. When the plane is 2 miles away, what is the rate of change of θ?

tan(θ)=h/x

A. dθ/dt=−6 degrees/second

B. dθ/dt=−4 degrees/second

C. dθ/dt=4 degrees/second

D. dθ/dt=6 degrees/second

answer: two angles are called supplementary if they add up to 180°. example: the two angles (140° and 40°) are supplementary because they add up to 180°.

step-by-step explanation:

a.)the line for function b is steeper

a sample of water is taken and kept in a beaker in a freezer at a constant temperature of 0°c. if the system is at dynamic equilibrium, which of these statements is true?  

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81