1. Simplify F(X) by dividing the denominator by the numerator in turn, then take the derivatives of each part first, then add and subtract, and then substitute the derivatives of F(X) into X= 1/4 to get 13. 2. Derive x on both sides at the same time, and get cosY*dy/dx+e∧x-y∧2-2xy*dy/dx=0, and simplify to get dy/dx=(y∧2-e∧x)/(cosY-2xy).3. When x = 3, the maximum value of y is 9 ∧ 1/3.4. V = 300m3 = SH = ∏ RRH, so H = 300/∏ RR, and because the material S = 2 ∏ RR+2 ∏ RH = 2 ∏ RR+2 ∏ R * 300/∏ RR = 2.