Philadelphia University Faculty Of Science Dep. of Basic Science and Math Business Mathematics (250105) Final exam Student Name : ------------------Student Number : ----------------المجموع 4 3 2 1 رقم السؤال العالمة Q1 : Choose the correct answer: 1. If A= a) 8/7 2 7 x 8 and │A│=8, find x b) 7/2 c) 14 d) -6/5 2. Find the set of solutions of log(x2-2x+1)=0 3 a) {-3,3} b) {0,2} c) {1} d) {-1,1} 3. Solve the equation 2x=8x-1 a) x= 3 b) x= -4 c) x= 7/3 2 1 3 3 4. If A= 3 2 & B= 2 2 , find AB d) x= 3/2 a) 8 8 d) 15 8 10 6 13 13 5. If A= a) 3/8 -1/4 -1/4 1/2 b) 8 8 13 13 2 3 4 2 c) 6 3 6 4 find A-1 b) 1/4 -3/8 -1/2 1/4 c) -1//4 1/2 3/8 -1/4 6. Which of the following is increasing function a) 2x+y= -7 b) 2x+3y= 3 c) -2x-y= 10 d) -1/4 1/2 3/8 -1/4 d) 5x-4y= 8 7. Let f(x)=3x2-3x+1. Find the equation of the tangent line of the curve f(x) at x=2 a) y=9x-11 b) y=3(3x+1) c) y=9x+3 d) y=3x+4 8. Find the critical point of f(x)=3x2+6x+1 which is minimum a) (1,2) b) (-1,-2) c) (0,1) d) (1,10) Q2 : Complete each of the following: Log x5 1) If f(x)=(10) , then f ′(x)= 5x4 8 3 8 2) If ∫ f(x)dx=6 and ∫ f(x)dx=- 8 then ∫ f(x)dx= 6- (-8) =14 2 2 3 3) ∫ e8lnx dx= x9/9+ C 4) If ex=7 and ey=3, then ex+y= 21 5) If f(x)=3x-5,then f - 1(1)= 2 6) If MR=18-4Q, then TR= 18Q-2Q2+C 3 7) ∫(4/x)dx= ln 81 1 8) If f(x)= (3x2-8)3, then f ′(x)= 18x(3x2-8)2 9) ∫ 2e-3x dx= (2e-3x)/(-3)+C 10) If f(x,y)= 4xy3-x3y+7, then fx at(1,2)= 26 2 3 11) If A = 4 2 and B= 3 7 5 6 12) If x = ln3 – ln5 , then ex= 3/5 T , then A+B = 5 8 11 8 Q3 : The demand and the supply function of a good are given by P=-Q2-4Q+68 , P=Q2+2Q+12 respectively Find : 1) The equilibrium point 2) The Producer’s surplus (PS) assuming pure competition. Answer: 1) Q = (4,36) 4 2) PS= 144 - ∫ (Q2+2Q+12) dQ 0 = 144-85.33 = 58.77 Q4 : Put the following system in a matrix form and solve it by Cramer’s Rule 3x + y - z = 0 2x – y + z = 1 -x + 3z = 2 Answer: 3 1 -1 2 -1 1 -1 0 3 x = 1/5 y = 2/15 z = 11/15 x y z = 0 1 2