Unit 3 Review for Common Assessment Match the graph of a quadratic function with it’s equation below: f(x) = x2 f(x) = -(x+2)2+4 f(x) = (x+2)2-1 Describe the end behavior of the graph of each given graph. x , f (x) x , f ( x ) x , f ( x ) x , f ( x ) x , f ( x ) x , f ( x ) Use the Leading Coefficient Test to determine the end behavior of the graph of the given polynomial function. 1.) f(x) = -x3 + 4x Rise Left, fall right x , f ( x ) x , f ( x ) EVEN 2.) f(x) = x4 – 5x2 +4 Rise left, rise right x , f ( x ) 3.) f(x) = x5 - x x , f ( x ) Fall left, rise right 4.) f(x) = x3 – x2 - 2x Fall left, rise right x , f ( x ) x , f ( x ) x , f ( x ) x , f ( x ) 5.) f(x) = -2x4 + 2x2 Fallleft, fall right x , f ( x ) x , f ( x ) Determine without graphing, the critical points of each function. 1.) f(x) = (x + 2)2 - 3 f’(x) = -2x + 6 f’(x) = 2x + 4 Min (-2,-3) 3.) f(x) = 3x3 - 9x + 5 f’(x) = 9x2 - 9 2.) f(x) = -x2 + 6x - 8 f’’(x) = 18x Max (3,1) 4.) = x3 + 6x2 + 5x Min (-.47, -1.13) Max (-3.53, 13.12) Pt. of Inflection (-2,6) Min ( 1, -1) Max (-1, 11) Pt. of Inflection ( 0 , 5) Min ( -√5, -16) 4 2 5.) f(x) = x - 10x + 9 Max (0, 9) Min ( √5 , -16) Find the zeros of each polynomial function. 1.) x2 – 40 = 0 2.) x3 + 4x2 + 4x = 0 x 40 x(x 4 x 4) 0 x x ( x 2)( x 2) 0 2 40 x 2 10 3.) x2 + 11x – 102 =0 ( x 17 )( x 6) 0 x = -17, 6 If you can’t figure it out then use Quadratic Formula 2 x = 0, -2, -2 4.) x2 + ¾x + ⅛ = 0 x 1 2 x 1 4 0 x = -½, -¼ Find the zeros of the polynomial function by factoring. 1.) f(x) = x3 + 5x2 – 9x - 45 1.) f(x) = x3 + 4x2 – 25x - 100 x ( x 4 ) 25 ( x 4 ) 0 2 ( x 25 )( x 4 ) 0 2 ( x 5)( x 5)( x 4 ) 0 x = 5, -5, -4 Which of the following is a rational zero of f(x) = –2x5 + 6x4 + 10x3 – 6x2 – 9x + 4 1, -3, -2, 4, -1 ???? Remember you could use synthetic division or just do p(x) and see if you get a remainder of ZERO OR p( 4 ) 2( 4 ) 6(4 ) 10 ( 4 ) 6(4 ) 9( 4 ) 4 5 4 3 2 So 4 is a factor, the others are not =0 Use synthetic division to divide x4 + x3 – 11x2 – 5x + 30 by x - 2 . Then divide by x + 3 Use the result to find all zeros of f(x). So you are left with: x2 -5 x2 x Then all the zeroes are: -3, C 5 R ,2 List all possible rational zeros of 1.) 2.) List all possible rational roots, use synthetic division to find an actual root, then use this root to solve the equation. f(x) = 2x4 + x3 – 31x2 – 26x + 24 Hint 4 and -3/2 are roots 2x2 + 6x – 4 USE QUADRATIC FORMULA!!! Find the number of possible positive, negative, and imaginary zeros of: 2,0 positive roots P N 2 0 I P 1 positive root 0 f ( x ) x 4 x 5 f ( x ) x 2 x x 2 x 2 2 4 0 0 3 2 2 0 negative roots 3,1 negative roots N I 1 3 0 1 1 2 3,1 positive roots f ( x ) 6 x x 4 x x 2 4 3 1 positive root P N I P 3,1 positive roots 2 3 1 0 1 1 2 f ( x ) 5 x 6 x 24 x 20 x 7 x 2 5 4 3 2,0 positive roots 2 3 3 1 1 N 2 0 2 0 I 0 2 2 4 Use the given root to find the solution set of the polynomial equation. p(x) = x4 + x3 – 7x2 – x + 6 GIVEN -3 IS A ROOT Then we can find the rest by factoring: x 2x x 2 3 2 x ( x 2) 1( x 2) 2 ( x 1)( x 2) 2 ( x 1)( x 1)( x 2) So the roots are: -3, -1, 1, and 2 Which equation represents the graph of the function? f(x) = 2x2+2x-1 f(x) = -x2-3x+4 f(x) = x2+10x-1 Approximate the real zeros of each function. R( x ) 3 x x 1 4 F (x) x 4 x 6 2 3 0.7, -0.7 H (x) 2 x 4 x 3 3 2.3 -2.5 G(x) x 3x 1 2 2 -0.4 and -2.6 Use the given root to find the solution set of the polynomial equations x x 8 x 4 x 48 4 3 x 3 x 12 x 54 x 40 2 4 2i Since 2i is a root, so is -2i Turn the roots into factors, multiply them together, then use long division ( x 2i)( x 2i) x 4 2 x x 12 3 x 4 x x 8 x 4 x 48 4 3 2 3-i Since 3-i is a root, so is 3+i Turn the roots into factors, multiply them together, then use long division ( x (3 i))( x (3 i)) x 6 x 10 2 x 3x 4 2 2 2 2 x 6 x 10 x 3 x 12 x 54 x 40 2 4 3 2 Then factor to find the remaining roots Then factor to find the remaining roots x x 12 ( x 3)( x 4 ) x 3 x 4 ( x 1)( x 4 ) 2 So the roots are: 2i, -2i, 3, and -4 2 So the roots are: 3-i, 3+I, 1, and -4 Find the vertical asymptotes, if any, of the graph of each function. R( x) x F (x) x 4 2 x = -2, x = 2 H (x) x x3 x4 x=4 x 9 2 2 G(x) x 1 2 No vertical asymptote x 4 x 21 2 x = -7 Find the horizontal asymptote, if any, of the graph of x R( x) F (x) x 4 2 y=0 H (x) G(x) 2 x 1 3x x If a monomial is on bottom then you just break it up. 2 x x 1 3 2 2 Otherwise must do long division 3x 3 x x 1 3x 0 x x 0 x 0 3 y=1 x4 y=1 4 x x3 2 4 3 2 y = 3x + 3 Choose the correct graph for the rational function x 1 2 R( x) x 2x 5x 2 2 F (x) x 4 2 H (x) x x 1 2 2( x 2) ( x 5) 2 2 G(x) ( x 5)( x 2) 2