a tank with a rectangular base and rectangular sides is open at the top. it is to be constructed so that its depth is 2m and volume is 8 .If building of tank costs rs 70 per sq metre for the base and rs 45 per sq for the side . What is the cost of least expensive tank ? I am getting 1000 rs becos width of each side cums to be 2 ..is it correct?

Question

kainui · Answer

Width? Don't you mean the girth of each side cums to be 2?

anonymous · Answer

width as in the measurement of each side...

kainui · Answer

Oh, right. Of course.

kainui · Answer

Also, since I have done many optimization problems in the past I can tell you that cubes and squares are generally the best bang for your buck. You're saying it's 2x2x2  then you're probably right.

anonymous · Answer

okay...thanx a ton!

anonymous · Answer

Find the equation of the line passing through the point (3,4) which cuts the first quarter a triangle with minimum area... .$$x=3y/y-4......Area=1/2xy=1/2 (3y/y-4)(y)=3y^2/2(y-4)...Differentiating....i get y=-8 ..$$...is it correct ?