hi. can u help to show the working with correct answer

SULIT SULIT SULIT SM015 SULIT SMO15 6 dy Cos then A function f (x) has a minimum value at x = c if S' (c) =0 and dx (a) f (x) changes sign from positive to negative as x passes through c (2) (cos,x + xsin.x) S' (x) changes sign from negative to positive as x passes through c (b) -cost + # rain.x (c) S'(x) does not change sign as x passes through c ( d) None of these (c) casx 4 180 *sin x 10 If the rate of increase of area of a circle is not constant but the rate of increase of perimeter is constant, then the rate of increase of area varies (a) as the square of the perimeter (b) inversely as the perimeter 7 (c) as the radius (d) inversely as the radius (a) (b) (c) (d) If x =1' +31 -8, y=213-21-5, then - at 1=1 is (a) (b ) (c) (d) None of these SULIT