# Need help with Precal Review Questions (Test this week)

• Sep 28th 2009, 07:52 PM
Gitano
Need help with Precal Review Questions (Test this week)
Hey guys, I have a Calculus test this week that covers some Precal materials and I am not quite sure whether the answers I got on a couple of my review problems are correct.

T/F

1. If f(s) = f(t), then s = t.
2. If X1 < X2 and f is a decreasing function, then f(X1) > f(X2).
3. If f and g are functions, then f o g = g o f.
4.You can always divide by e^x.
5. If x>0, then (ln x)^6 = 6 ln x.
6. The parametric equations x = t^2, y = t^4 have the same graphs as x = t^3, y = t^6.

7. Express the function F(x) = 1/sqrt{x + sqrt{x} } as a composition of three functions.

Any feedback or help would be greatly appreciated.
• Sep 28th 2009, 08:05 PM
pickslides
Quote:

Originally Posted by Gitano
6. The parametric equations x = t^2, y = t^4 have the same graphs as x = t^3, y = t^6.

well

\$\displaystyle x = t^2\$

\$\displaystyle y = t^4\$

\$\displaystyle y = (t^2)^2\$

\$\displaystyle y = x^2\$

and

\$\displaystyle x = t^3\$

\$\displaystyle y = t^6\$

\$\displaystyle y = (t^3)^2\$

\$\displaystyle y = x^2\$

So this is true but do you have some reasons you can post here about the others? Is there any value knowing if a handful of questions are true or false?

Wouldn't it be better to know the ideas and methodology behind such questions?
• Sep 28th 2009, 08:17 PM
Gitano
^^^

I hear what you are saying, I guess it is just because I have a test in a couple of days and just wanted a second opinion on if my answers were correct, to make sure I have the right understanding.

Thanks anyways.
• Sep 28th 2009, 08:49 PM
pickslides
Quote:

Originally Posted by Gitano
and just wanted a second opinion on if my answers were correct,