Calculus Question (1 Viewer)

[chingyloke]

Find the max possible area if a straight 8m length of fencing is placed across a corner to enclose a triangular space.

Can anyone lend their expertise?

 

[Timothy.Siu]

Find the max possible area if a straight 8m length of fencing is placed across a corner to enclose a triangular space.

Can anyone lend their expertise?

let b=base and h=height of the triangle thing...

b²+h²=8²

A=0.5xbxh
A²=0.25xb^2xh^2

A^2=0.25xb^2 (64-b^2)
=0.25x(64b^2-b^4)

dA^2/db=0.25(128b-4b^3)
dA^2/db=0 when b(32-b^2)=0

b=sqrt 32
h=sqrt 32

sorta dodgey working out, hope u understand,

 

[chingyloke]

understood perfectly. thankyou.