Question

P(t) = 8 - 2(squareroot)2t + 4

Answer 1

Step-by-step explanation:

P(t) = 8 − 2√(2t + 4)

The x-intercept(s) is where t = 0.

P(0) = 8 − 2√(0 + 4)

P(0) = 8 − 4

P(0) = 4

The y-intercept(s) is where P = 0.

0 = 8 − 2√(2t + 4)

2√(2t + 4) = 8

√(2t + 4) = 4

2t + 4 = 16

2t = 12

t = 6

So the intercepts are at (0, 4) and (6, 0).

The easiest way to tell if the function is increasing or decreasing is to graph it.  Otherwise, we have to either use calculus to find the derivative, or assume the function is constantly increasing/decreasing and use limits.

lim(t→∞) P(t) = -∞

The function is decreasing.