Pre-Calculus - Logarithms

[Kerryemccarthy]

a^(1/2)(a^(3/2)-2a^(1/2))

I just need to know how to get it started please. Also is this one I can punch into my calculator?

 

[tkhunny]

You must first have just a little more courage. Why use your calculator? Are you building a table of values? In any case, let's make your life a little easier.

1) Factor out a^(1/2) from the large expression inside the parentheses. See if that leads anywhere.

2) Assign a variable, aka make a substitution. n = a^(1/2) -- Your expression becomes n(n^3 - 2n). That's a WHOLE lot easier.

 

[Mrspi]

a^(1/2)(a^(3/2)-2a^(1/2))

I just need to know how to get it started please. Also is this one I can punch into my calculator?

Or, you could multiply each term INSIDE the parentheses by the a[sup:1xj2zznn](1/2)[/sup:1xj2zznn] which is outside, and then simplify.....

a[sup:1xj2zznn](1/2)[/sup:1xj2zznn] * a[sup:1xj2zznn](3/2)[/sup:1xj2zznn] - a[sup:1xj2zznn](1/2)[/sup:1xj2zznn]*2 a[sup:1xj2zznn](1/2)[/sup:1xj2zznn]

Remember the rule for exponents which says "when you multiply two powers of the same base, you ADD the exponents."

Apply it to the two products, and see if you get something that's easier to work with.