6.4 Determine the lowest positive root of f(x) = 7 sin(x)ex-1: (a) Graphically. (b) Using the Newton-Raphson method (three iterations, x¡ = 0.3). (c) Using the secant method (three iterations, x;-1 = 0.5 and x; = 0.4. (d) Using the modified secant method (five iterations, x = 0.3, 8=0.01).