Which area formula or formulas show(s) a joint variation? i. v = s^3ii. a = b x hiii. c = πd (this is the pie symbol next to the d)a) i, ii, and iiib) iii onlyc) ii and iiid) ii only

Option d

ii only.

Explanation:

1) V=s^3 got only one variable s.  Hence when s is changed V is changed and vice versa.  Not joint variation.

2) A=bxh

Here when area changes either b can change or h can change or both.  For example if area 8 (4x2) is changed to 16, we can have either length unchanged (4x4) or width unchanged (8x2) or both changed as (4x4)  Thus there is a joint variation for b and h here.

III.c=pi d

Here d is independent variable and c dependent variable.  When d changes c changes directly and there is no joint variation.

So answer is d.