Question

PLEASE HELP WILL MEDAL

Evaluate a^a when a equals -2.
-4
4
1/4
-1/4


A $20,000 business computer depreciates at a rate of 15% per year. Which of the following equations would model the value of the computer?
y=20000(0.15)^x
y=20000(0.85)^x
y=20000(1.15)^x
y=20000+15x

Answer 1

@Mehek14 Can you help?

Answer 2

when exponent is neg, take reciprocal
\[(-2)^{-2} = \frac{1}{(-2)^2} = \frac{1}{4}\]

Answer 3

for an exponential model of form
\[y = A(1+r)^x\]
where r is rate of increase or decrease
here it is decreasing by 15% so r = -.15

Answer 4

@dumbcow is this for the second question or first?

Answer 5

@welshfella can you help?

Answer 6

i answered both

Answer 7

Ohh okay, so the first answer is 1/4?

Answer 8

And then the seoncd would be..? Sorry, got confused

Answer 9

@dumbcow

Answer 10

y=20000(1.15)^x ?

Answer 11

the growth = 1+r

r is rate (positive for increasing, neg for decreasing)

so if function is decreasing then 1+r < 1

r = -0.15 ----> 1+r = 1-.15 = .85

Answer 12

so it would be y=20000(0.85)^x ?

Answer 13

@dumbcow

Answer 14

???

Answer 15

They were correct, thank you very much (: