A parcel in the form of a rectangular block is held together by three pieces of tape as shown in the diagram . The parcel has square ends of side x cm and is y cm in length. Express the total length of tape in terms of x and y. Given tat the total length of tape is 450 cm, express the volume, V cm3 (cubed), of the parcel in terms of x. Find the value of x and of y for which V has a stationary value and determine whether this value is a maximum or minimum.

Question

A parcel in the form of a rectangular block is held together by three pieces of tape as shown in the diagram . The parcel has square ends of side x cm and is y cm in length. Express the total length of tape in terms of x and y. Given tat the total length of tape is 450 cm, express the volume, V cm3 (cubed), of the parcel in terms of x. Find the value of x and of y for which V has a stationary value and determine whether this value is a maximum or minimum. 
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