evaluate the function f(x)=4•7^x for x=-1 and x=2 . show your work.

Question

evaluate the function f(x)=4•7^x  for x=-1 and x=2 . show your work.

bibby · Answer

just plug in the values and evaluate. recall that $\large x^{-n}=\dfrac{1}{x^n}$

anonymous · Answer

is that the answer? i dont know how to do this.. I've been stuck on this question for days

bibby · Answer

is what the answer? the answer is 2 different numbers. plug in x= 2 and evaluate

anonymous · Answer

I'm confused!! I really can't do this crap. if I did that then it'd be 2^-n=1/2^n . how the hell am I supposed to evaluate that?

bibby · Answer

$\huge f(x)=4*7^x\x=2\\large f(2)=4*7^2$

bibby · Answer

we're trying to find f(-1) and f(2)

anonymous · Answer

okay but how do you do that

bibby · Answer

use a calculator? have you not learned exponents yet?

bibby · Answer

the number up on top represents how much times it multiplies itself.

for example $3^2=3*3\6^3=6*6*6 $

anonymous · Answer

I don't have a calculator or else I would. & yeah I have. but all these variables and cramp confuse me. obviously I need help or I wouldn't have asked the question

anonymous · Answer

ok

bibby · Answer

so just expand and multiply by hand

bibby · Answer

chill out with the attitude yo, I have homework I'm not doing right now, be grateful

bibby · Answer

what is    7^2?