Which of the following functions grows the fastest as x grows without bound?

Question

f(x)=x^2
g(x)=x^2+5x <<<<MY ANSWER
h(x)=(sqrt x^4+2x)
They all grow at the same rate

Compare the growth rate of the functions f(x)=4^x and g(x)=(sqrt 16^x+2^x)
f(x) grows faster than g(x)
g(x) grows faster than f(x)MY ANSWER
f(x) and g(x) grow at the same rate
it cannot be determined

There is a graph that starts at (-4,0) it then goes to (-2,-2) it goes through (0,0) as it goes to (2,2) and ends at (4,0)
Where is this graph concave up?
(-4,-2) U (2,4)
(-2,2) MY ANSWER
(-4,0)
(0,4)

Answer 1

#1 ok
#2 4^x grows faster than any polynomial
#3 I think more likely (-4,0), as in
y = 2sin(pi/4 x)

http://www.wolframalpha.com/input/?i=2sin(pi%2F4+x)

Answer 2

Thank you!