How far apart are the foci of an ellipse with a major axis of 34 feet and a minor axis of 16 feet? a. 15 ft b. 12 ft c. 9 ft d. 30 ft
If the major axis is 34, what is the value of "a" ?
\(\bf c=\sqrt{a^2-b^2} \\ \quad \\ c=\textit{distance from the center to either foci}\)
so as @Mertsj said, get the value for the "a" component and the "b" component or minor axis, and solve for "c"
|dw:1393292056636:dw|
Are you there, Tim?
Yes I'm here now, sorry my dad called me. Give me a few secs to go over what you guys wrote c;
\[c=\sqrt{34^2-16^2}\] Do I first solve this?
\[c=\sqrt{1156 - 256}\] \[c= 30\]
Is that it ?
@jdoe0001 or @Mertsj ?
That is why I asked you to identify the value of a. Look at the picture. the length of the major axis is 2a.
a=17 b=8
how did you get that?
\[c=\sqrt{289-64}\] \[c= \sqrt 205\] \[c= 14.32\]
Now you can answer the question the problem asks.
I'm still not positive 15 ft?
T|dw:1393292779288:dw|
The focal points lie on the major axis. Each focal point is c units from the center. So the distance between the foci is 2c
2* 14.32 = 28.64 which is approximetly 30 ft?
is that correct?
yes
Thank you!
I think you make a mistake in your calculation.
289-64=225
so c = 15 and 2c = 30
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