Question

Evaluate the function rule for the given value. Y=6*4^x for x=-3

Answer 1

y = 6 x 4^x. x = -3

you change x in the equation for -3

y= 6 x 4^ -3

if you do it in the calculator, remember to put parenthesis in between -3

y = 6 x 1/64

y = 3/32 or 0.09375

Answer 2

`y = (3)/(32)`

Explanation:

Using the exponent rule:

`a^(-n) = (1)/(a^n)`

Given the function:

`y = 6 \cdot (4)^x` ......[1]

To evaluate the function rule for x = -3.

Substitute x = -3 in [1] we have;

`y = 6 \cdot (4)^(-3)`

⇒
`y = 6 \cdot (1)/(4^3) = 6 \cdot (1)/(64)=(3)/(32)`

Therefore, the function rule for the given value when x = -3 is:

`y = (3)/(32)`