The number of distinct real roots of x-4x+1 = 0 is: 6. (a) 4 7. (b) 2 (c) 1 (d) 0 The lengths of the sides of a triangle are 10 + x2, 10+ x2 and 20 - 2x. If for x = k, the area of the triangle is maximum, then 3k is equal to: (a) 5 8. If cos =loge 2 5 ().lv|