Just differentiate <em>G</em> and <em>H</em> :
• d<em>G</em>/d<em>x</em> = d(<em>x</em> ² <em>eˣ </em>)/d<em>x</em> = 2<em>x</em> <em>eˣ</em> + <em>x</em> ² <em>eˣ</em>
so <em>G</em> is not an antiderivative of <em>f</em>.
• d<em>H</em>/d<em>x</em> = d(2<em>x</em> <em>eˣ</em> - 2<em>eˣ</em> ) = (2<em>eˣ</em> + 2<em>x</em> <em>eˣ</em> ) - 2<em>eˣ</em> = 2<em>x</em> <em>eˣ</em> = <em>f(x)</em>
so <em>H</em> is indeed an antiderivative of <em>f</em>.
Answer:
Vertex form is

where (h,k) is the vertex
So our vertex form is

It passes through (6,0) so we have

Solve for a.



So our equation is

In general an annual rate of

compounded monthly will multiply the amount by a factor of

each month.
Each month of 4.3% is a factor of

. That goes for five months, so is multiplied by itself five times, so gets a fifth power.
Each month of 13.7% is a factor of

. He pays this for 12-5=7 months, so it gets an exponent of seven.
We started the year owing $2600 of principal, so after the year we owe

.
Choice A.
When the last child has finished his or her schooling and is no longer dependent on the parents, the Echo stage begins. This is the pre-retirement or "empty nest" stage. For those individuals without children, the Echo stage begins about 10 years before retirement.