Question

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

Hey guys can someone please help me, what do I do to find the intercepts and how do I know if the graph is increasing or decreasing
Help plz!!!

Answer 1

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.