4. The denite integration 0'3 m [Lu 5% II we can be derived using the following method. Let (a) Give a reasonable argument to show that 122/ / e(m2+y2)d$dy 0 0 (b) Convert the above double integral to one Wittern in polar coordinates (r, 6). (c) Solve the double integral to obtain I2. [6 marks] 5. The mass M of a curve Wire with a nonuniform density can be found using line integral M:/ p(a:,y?z)ds C Where p(:1:, y,z) is the mass density function. Given that k a: : k 0 p(w7 y} 2) 1 + yz 7 > 5 nd the mass of a thin Wire shaped in the form of the helix 1: = 3005 t, y = 3sint, z 2 4t , 0 S t S 7r/2. [6 marks]