please show all your work to help me better understand. and please only answer using calculas 1 formulas and equations. Thank You!

3. A rectangle is located with its base along the x axis, one corner at (8, 0) and the opposite corner on the graph y = vix for some 1 s r S 8. For what value of x E [1,8] is the area of this rectangle the largest? Please show all calculus. You may use your calculator to solve algebraic equations, but be sure to show me what you are putting into your calc. Round to three decimals if your calculator does not give exact values. 10