Question 5a, 5b. Precalc 11, thanks
McGra By that you did in order to solve. You must solve at junction, explain why you u to use for which function. by factoring, but you may choose which method to function by comp used the a = 3 b = 8 square and one by factorin -12 (n) 1= 3n'+ 8n+4 0 = 3n 2 + 8n + 4 0 = (8n . 2 ) (n + 2) an 2 + 6n + 2 1 Name: Carina Li factoring bed -0.0612 + 1.81 + 3 where h(1) is the height in meters and t is the time in seconds. 4. An angry bird travels in a parabolic shape towards its target. Its height above the ground is defined by h(1) = What maximum height does the bird reach? (2 marks) Pre "h(t ) = - 0 . 06t2+ 18t + 3 ( no roots giver - 0.06 ( t 2 + 30t ) +3 olve tan 0 = -1.724 for 0 for = - 0106 ( t 2- 30t +225- 225) +3 = - 0.06 ( +2 - 30t +225)+3+13.5 Answer: _16 .5m = tan ' (- 1.724) 59. 880 (b) y = 423+201 +25 0 = 4 x2+20 X - 1.8 = - 0.06 ( t - 15)2 + 16.5 - 1.8 = 180-59.88 = = ( 2* + 5 ) 20 2(-0.06 ) = - 0.12 , = 15 360 - 59188 = = ( 2 * + 5 ) WIN 0 = 4 x 2 + 201 When does the bird reach its maximum height? (1 mark) h = c - at 2 = 3 - ( - 0 . 0 6) ( 15 ) - = 3 - ( - 0 . 06 ) ( 2 25 ) = 3 - 6- 13.5 ) = 16.5-56 2 / = 4 x2 + 10 * cos 0 = - ; and tan 8 > Answer : _IS S raw the angle in standard (no roots = ( 2 * +5 )0 given ) (2x + 5 = positive (c ) 1 = 102 - 6 0 = 492 - 6 C . What is the y-intercept? What does the y-intercept represent? (2 marks) y - intercept is when x is o ermine the exact ratios O = -03/02- 4 h(t ) =- 0.06 (t= 15)2+165 62 = 72 2 (4 Y = - 0 106 (0 - 15 ) 2 + 16:5 Answer(s): Hint: (0 , 3) / 24 - 03 /0+ 0 Y = -20 106 ( 225 ) + 16 :5 represents the height it 24 = -13.5 + 1615 started above ground 8 3 1. 61 = mine the measure of a = - 07/ 96 8 5. A rectangular playground next to a school will be enclosed by 140 m of fencing (3 sides). Sinc- 124 / 7 (a) What will be the length and width of this playground to provide the maximum area? (2 marks) A = l . W = x . y 44. 40 School 4. Explain the use of the zero 140 = / 24tix Answer: 17, Sm, 8:75m X ine coordinates for The zero prod Fence Fence 24 = 140 - X V : ( 17.5 , 153. 125 ) 2 numbers m Fence Y = 70 - 1/2 X T one of the ny by determining me because anytr A = X . ( 70 - 1/ 2 x ) max area ZA = 290. Draw a the product W = 153. 125+ 175 numbers my = 70x - 1/2 x2 8.75 m = W ex . ( x + 4 ) ( x - = - 1/2 x 2 + 70x $76 cm * + 4 = 0 X - = - 1/2 ( X2 - 35x) 1 / 2 B * = - 4 OR X : = = 1/2 ( X2 - 35x+306.25- 306.25) cm = - 1/2 ( X 2 - 35 X + 306,25 ) + 153. 125 - 1/2 ( X - 17.5)2+ 153, 125 90 (b) What is the maximum area? (1 mark) S either o Answer : 153. 125 m 2 to get m 2 3cm 62
