Thursday

October 23, 2014

October 23, 2014

Posted by **nesri** on Tuesday, October 5, 2010 at 8:07am.

- calculus -
**Reiny**, Tuesday, October 5, 2010 at 9:28amyour parabola is y = 5 - (1/5)x^2

let the points of contact of the base of the triangle be (x,y) and (-x,y)

Then the area is

Area = xy/2

= (x/2)(5-(1/5)x^2)

= 5x/2 - (1/10)x^3

d(Area)/dx = 5/2 - 3x^2/10

= 0 for a max of Area

3x^2/10 = 5/2

x^2 = 25/3

x = ± 5/√3 or appr. 2.88675

sub back in area expression

I had appr. 4.81125

( I tried x = 3 and x = 2.8 and they both gave me slightly smaller areas)

- Correction - calculus -
**Reiny**, Tuesday, October 5, 2010 at 9:45amThe base of the triangle should have been 2x, which makes the

Area = xy

= 5x - (1/5)x^3

Can you figure out how that changes the answers?

(hint: one stays the same, ...)

**Answer this Question**

**Related Questions**

math - 9. An isosceles triangle is drawn with its vertex at the origin and its ...

Calculus - The area of largest isosceles triangle that can be drawn with one ...

Math - An isosceles triangle has its vertex at the origin and the ends of its ...

calculus - A rectangle is inscribed in an isosceles triangle. If the sides of ...

CALCULUS 2 - Use calculus to find the volume of the following solid S: The base ...

calculus - #3 A solid has a base in the form of the ellipse: x^2/25 + y^2/16 = 1...

calculus - The base of a certain solid is the triangle with vertices at (-10,5...

Calculus - The base of a certain solid is the triangle with vertices at (-10,5...

calculus - The base of a certain solid is the triangle with vertices at (-14,7...

Geometry - The two vertices that form the base of an isosceles triangle are (-5...