Equation of an ellipse
→having center (0,0) , vertex ( and covertex
and focus
is given by:
As definition of an ellipse is that locus of all the points in a plane such that it's distance from two fixed points called focii remains constant.
Consider two points (a,0) and (-a,0) on Horizontal axis of an ellipse:
Distance from (a,0) to (c,0) is = a-c =
Distance from (-a,0) to (c,0) is = a + c =
a -c + a +c
= a + a
= 2 a →(Option A )
$390 is the interest will Charlie’s initial investment earn over the 15-year period. The money does Charlie have after the 15 years is $715.
<u>Step-by-step explanation:</u>
Harlie invests $325 in an account.
<u>The formula to find the interest will Charlie’s initial investment earn over the 15-year period :</u>
⇒ <u></u>
⇒
⇒
Therefore, $390 is the interest will Charlie’s initial investment earn over the 15-year period.
<u>Money Charlie has after 15 years :</u>
It is given by the formula,
⇒ Amount = Principal + Interest.
⇒ 325 + 390
⇒ 715 dollars.
∴ The money does Charlie have after the 15 years is $715.